Ovulation and your fertility are closely linked. Your fertility waxes and wanes throughout the month (or rather, throughout your menstrual cycle) and if you know when you’re going to ovulate, you’re able to focus your attempts to conceive on the time when you’re most likely to conceive.
Today we’re taking a look at ovulation and fertility, starting with answering that key question: when does ovulation occur?
When do you Ovulate?
You don’t ovulate on a fixed calendar schedule, but rather due to your body’s menstrual cycle, which does not line up with the calendar. The menstrual cycle exists to prepare your body for pregnancy – and to reset and prepare again if you don’t get pregnant.
Ovulation occurs at approximately the half-way point, though when that is depends on the length and regularity of your cycle. Your cycle begins with your period – a useful marker that, when you record it across multiple cycles, can tell you how long and how regular your cycle is. At the same time your ovaries begin to mature eggs in small, fluid filled sacs called follicles. This process is caused by the secretion of a hormone called LH – Luteinising Hormone. At the end of the ‘follicular phase’ of your cycle, a big surge of LH causes you to ovulate. You can get tests (known as Ovulation Predictor Kits or OPKs) that test your urine for this hormone surge, telling you when you’re ovulating.
Your body temperature is also affected by your menstrual cycle, and if you take a temperature reading as soon as you wake up, before you metabolism starts heating up your body, you can chart how it changes across the month and look for the patterns that herald ovulation.
Your fertile window doesn’t start when you ovulate. If you’re only looking for when ovulation happens you’re leaving yourself with only one, or at most two fertile days.
Sperm can survive up to five days in a woman’s body after ejaculation, which means the fertile window starts five days before you ovulate. The egg is viable only for a maximum of twenty-four hours which means your fertile days end the day after you ovulate: the egg cannot be fertilised after this.
To get the full benefit of your fertile window, you need to either use a method of ovulation tracking that can predict when you will ovulate more than five days in advance (like progesterone testing) or apply what you’ve learned to your next cycle.
If your BBT tracking and OPK tests confirm you ovulate on the fourteenth day of your cycle, and your cycle is regular (ie. it’s the sae number of days each time) then you can rely on ovulating on the fourteenth day of your cycle in future. This means that you can plan on your fertile window beginning five days before that, and start trying to conceive from the ninth day of your cycle!