If you’re TTC, you are likely familiar with the term ‘ovulation.’ However, if you find yourself asking, What is ovulation?, don’t worry, we’re here to break it down for you. 

We’ll also be discussing which tracking methods are the most reliable, signs to watch for that indicate ovulation, and how to improve your chances of becoming pregnant by using them. 

Ovulation occurs when a mature egg is released from the ovary. It is a part of the menstrual cycle, which is the hormonal process a woman's body goes through each month. Understanding ovulation is vital because it plays a major role in getting pregnant. 

Although many women now use freely available period tracking apps, they sometimes only find out about tracking ovulation when they are trying to conceive. Understanding ovulation and learning how to track your cycle can not only improve your chances of getting pregnant, but also provide insights into other important factors that may influence your cycle. 

At first, cycle tracking may seem a little confusing when you’re trying to decipher the difference between OPKs, BBT, and more, so we’re here to help. In this blog, we’re sharing everything you need to know about ovulation — what all those cycle-tracking acronyms mean, ovulation’s role within the menstrual cycle as well as common symptoms and signs to watch for, how to reliably and accurately track with OvuSense, and more.

Understanding Your Cycle

To learn more about ovulation, it’s important to gain an understanding of your menstrual cycle as a whole. There are four phases of your cycle: the menstrual phase, the follicular phase, the ovulation phase, and the luteal phase. Each phase has its own unique purpose and ultimately helps with reproduction. 

  • Menstrual Phase: The first phase of the menstrual cycle is most commonly referred to as your period. Typically lasting anywhere from 3-7 days, symptoms during this time can include fatigue, cramps, bloating, mood swings, and irritability.
  • Follicular Phase: The follicular phase begins on the first day of your period (so there is some overlap with the menstrual phase) and ends when you ovulate. During this phase, higher estrogen levels make your uterine lining grow and thicken. The lining becomes rich in nutrients to prepare for a possible pregnancy.
  • Ovulation Phase: Next up is the ovulation phase. You can tell you’re ovulating by a slight rise in body temperature and thicker discharge that has the texture of egg whites. This phase only lasts about 24 hours. You may also have heard of the Fertile Window – that’s the key time for baby dancing!  It starts around 5 days before ovulation and finishes at the end of the Ovulation Phase.
  • Luteal Phase: The last phase of the menstrual cycle is the luteal phase. During this time, you may experience symptoms such as bloating, breast swelling, pain, or tenderness, mood changes, headache, weight gain, changes in sexual desire, food cravings, and trouble sleeping. While this phase typically lasts anywhere from 11-17 days, certain ovulatory conditions can affect your luteal phase length. 

What Are Reproductive Hormones?

Before we discuss ovulation and cycle tracking, it’s really helpful to know what we’re looking for with these tracking methods. Your menstrual cycle works on the basis of four hormones that work together as a team from the start of one period until the start of the next.  Each of the four ‘team members’ has a name and sometimes it’s easy to tell from the name what their job is.  

  • Follicle Stimulating Hormone (FSH) – as the name suggests, FSH stimulates egg development and the release of estrogen 
  • Luteinizing Hormone (LH) – stimulates the release of the egg (ovulation) 
  • Estrogen – helps the lining of your uterus to grow 
  • Progesterone – is released during ovulation, helps maintain the lining of the uterus, and sustains the growth of the embyro after it implants   

If we want to track ovulation, the two key hormones we need to watch out for are LH and Progesterone. LH is expressed directly in the urine so can be measured there. Progesterone is not directly expressed in urine (although it can be measured by looking at another marker). The good news is that when Progesterone is released temperature rises, and when levels of Progesterone fall, then temperature falls – and it does this in a predictable way.  

OPKs, BBT, BFP, cCBT – Oh My!

You’ve likely heard about the different methods of identifying when you ovulate, but even if you’re not new to cycle tracking, it’s useful to understand the benefits and drawbacks of those methods in detail. 

Below, learn about the difference between OPKs, BBT, a fertility bracelet, and why cCBT with OvuSense may be your best bet. 

  • Ovulation Predictor Kits (OPKs) – OPKs are kits used to detect the rise in LH. It’s recommended you try and test twice a day and if you get two positives in a row, this tells you that ovulation is expected to happen in the next 24-36 hours. This is where many women will start their tracking journey. If you’ve got regular cycles with no issues, then LH strips may be a good place to start. However, they can’t confirm that you ovulated, or if you have no ovulation in a cycle (anovulation). Added to this if you have Polycystic Ovaries (PCO) or Polycystic Ovarian Syndrome (PCOS), you are likely to have high levels of LH at other times of the month, which can produce 'false positives' leading to confusion over when to try and get pregnant. However, even in women without PCO or PCOS, it is widely documented in the clinical literature that OPKs can produce ‘false negative’ results. That can mean using many tests throughout a cycle without ever knowing if you are about to ovulate. There are also Fertility Monitors with LH strip technology, which improve the usability of single test strips and sometimes help test other hormones like your Estradiol (Estrogen) level but the drawbacks of using them if you have issues with your ovulation remain the same.
  • Basal Body Temperature (BBT) – BBT is often used as a cheap and easy means of tracking ovulation. By taking a single waking oral temperature first thing in the morning, this method detects your ‘basal’ (lowest) temperature which will have occurred overnight. This is tricky and made more inaccurate because oral thermometers only have an accuracy of around 0.1 degrees Celsius (0.18 degrees Fahrenheit), so are not easily able to detect the 0.1 degrees Celsius (0.54 degrees Fahrenheit) rise associated with ovulation with accuracy. BBT can be used to predict your Fertile Window for your following cycle but it can be really unreliable if you have any variability in your ovulation timing or cycle length.
  • Fertility Bracelet  – Fertility bracelets are worn like a watch and take many readings of temperature from the top side of the wrist, instead of one reading like BBT. They have the benefit of providing nearly continuous tracking. Unfortunately, measuring skin temperature in that way makes it difficult to overcome the variations caused by the environment outside the body. We shiver to get warm and sweat to cool down – and that often means the skin surface temperature is moving in the opposite direction to the body temperature. The most important point about oral and skin-worn temperature measurement, though, is that they are unable to predict ovulation using your current cycle data. That means they don’t work for women who have any degree of variability in their ovulation, because the predictions they provide assume that the user ovulates at the same time every month.
  • Continuous Core Body Temperature (cCBT) – OvuSense measures cCBT overnight every five minutes by using a thermistor with a resolution of 0.003 degrees Celsius (0.054 degrees Fahrenheit). The OvuSense algorithm intelligently filters the data to provide the truest representation of the action of progesterone on the ovaries. OvuSense’s unique patented cCBT technology enables it to provide prediction of ovulation up to 24 hours in advance using current cycle data with a positive predictive value of 96% - that means unlike BBT or a Fertility Bracelet, it can provide the type of result that an LH test provides. It then goes on to confirm the exact date of ovulation with 99% accuracy, or tells you if you haven’t ovulated. Knowing when you’re about to ovulate, and exactly if and when you ovulated is key to improving your chances of successful conception. The last benefit of cCBT is it shows the pattern of Progesterone over your whole cycle, and that can provide vital insight for improving your chances, from the effect of a healthy diet or reducing alcohol intake, or taking supplements right through to if you need to take treatments for ovulation stimulation. 

Recognizing Discomfort  

For some, it is normal to experience discomfort around and during ovulation. While it is most common to feel some pain during the luteal and menstrual phases, certain women also experience pain during ovulation – known as mittelschmerz. The pain of ovulation can range from a mild twinge to severe discomfort and usually lasts from minutes to hours. These sensations are generally described as a twinge or pop, and you may also feel a burning sensation caused by the release of fluid from the follicle when the egg is expelled. Pain is generally felt on one side of the pelvis or abdomen, and sometimes can be accompanied by a small amount of vaginal bleeding or discharge. If you are experiencing pain in areas you don’t normally feel pain during your cycle, or if the pain lasts longer than normal, consult a physician. However, you may get to recognize this discomfort from one cycle to the next. It’s a useful clue that your cycle is progressing but studies show it’s not a very good way of understanding the day on which you ovulate.

Knowing The Symptoms  

In addition to discomfort, women may experience additional symptoms around ovulation. When ovulation occurs, your body temperature will rise by up to 0.54 degrees Fahrenheit in a 3-day window. If you’re tracking with OvuSense, you will be alerted of this through your app as your core body temperature rises. 

Changes in cervical mucus are also really noticeable for some women during ovulation. Normally, cervical mucus consists mostly of water, but during ovulation, discharge becomes thinner, stretchy in texture, and clear in color. You also may notice a greater volume of discharge during this time. Other signs of ovulation include tender breasts and bloating — but these indicators are less reliable as they are also associated with the luteal and menstrual phases. 

Tracking & Improving Your Chances with OvuSense 

After learning everything there is to know about ovulation, you may now find it helpful to learn about your complete cycle using OvuSense. 

By using your OvuSense sensor every night, the dedicated OvuSense App will predict ovulation using information from your current cycle, then confirm it and provide you with a full 8-day Fertile Window in your next cycle. That way, you’ll know the best time to get down to baby dancing. 

Track everything from the comfort of your home but with the knowledge that with the OvuSense Pro upgrade, you and your physician can gain extra insights. Take control of your fertility journey with OvuSense today!