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Your Fertility Cycle Explained

If you’re trying to get pregnant you’ll need to understand your fertility cycle. Your fertility doesn’t change across your lifetime, it also has peaks and troughs from month to month – or, more accurately from cycle to cycle. There are times in your menstrual cycle when your chances of conceiving successfully are close to zero, and a ‘fertile window’ when you are at your most fertile and stand the best chance of getting pregnant.

Your cycle begins with the first day of your period – that’s the first day of full bleeding, rather than spotting. If you’re tracking your cycle on a calendar or an app, you’ll want to note this day. At the same time as your period is removing the results of the previous cycle from your body, your follicular phase is beginning.

In the follicular phase your body is preparing as many as twenty eggs for eventual ovulation. Cued by the Luteinising Hormone, secreted in the Pituitary Gland, they grow in small, fluid-filled sacs in the ovaries which are known as follicles. Over the course of around two weeks they grow, with the biggest and most healthy egg (or, rarely, two of them) are ejected from the ovaries in a surge of LH. The smaller eggs are painlessly and harmlessly reabsorbed by the body.

It’s around this time that you are at your most fertile. The egg will be viable for between 12 and 24 hours, so if sperm can encounter it in this time, you stand the best chance of conceiving successfully. As sperm can survive for around five days after ejaculation this gives you a fertile window of six days, anchored by your ovulation date.

Your fertility cycle doesn’t end with when you ovulate – after the follicular cycle and ovulation, the second half of your menstrual cycle is made up of the Luteal Phase.

In the Luteal Phase, your uterus, cued by hormones secreted by ‘Corpus Luteum’, a temporary endocrine structure in your ovaries, begins to create a thick lining. It’s this lining that a fertilised egg will anchor into as it splits and grows into an embryo. It’s also the foundation of the placenta, the temporary organ which provides the embryo with nutrients as it grows.

If the egg is fertilised, it will travel through the fallopian tubes and into the uterus, where it attaches to the endometrial lining. If the egg isn’t fertilised it degrades and is ejected from the body with the rest of the lining in your period, as your fertility cycle resets.

To learn more about your cycle and hear from Ovusense customers visit ovusense