The Follicular Phase and Ovulation

Feb 22, 2022 | 2 minutes Read

The follicular phase is the time from day 1 of your period until the day on which you ovulate. On average, this lasts for around 13 or 14 days in women who have 28-day menstrual cycles. So even before your period is phasing out, your body is already preparing to release another egg in around 9 days.

But before this can happen, the eggs containing follicles in your ovaries need to be primed and nurtured so they can help support a number of follicles towards maturity. At this early stage, it’s still unclear which follicle will be the “chosen one” or the dominant follicle to become the egg of the month. So the chances are optimized for a healthy, mature egg to be released, your body will prepare lots of follicles just in case. As your levels of follicle stimulating hormone decrease, only one follicle will continue towards complete maturity.

By around day 9 or 10 of your cycle, this follicle will mature into an egg, and the others will just die away and be reabsorbed by your body. During this follicular phase, the lining of your uterus, which is called the endometrium, will be getting thicker and more engorged with blood and fluids. This is so that in the case of a pregnancy occurring, the newly fertilized egg can be well nourished.

Female egg production

When a baby girl is born, she has around 1 million ovarian follicles. This is all she will ever have—and certainly more than she will ever need—throughout her lifetime. Each of these follicles contains a single immature egg. By the time she reaches puberty, the majority of these will have been reabsorbed by her body. By the time she starts having periods, only around 400 will remain. This lifetime quota of follicles or immature eggs is nature’s way of maximizing the number of times conception could potentially occur.

This is different to men who can continue to make sperm throughout their lifetime. However, similar to a woman’s eggs, the quality of sperm and chances of conceiving are reduced by advancing age.

Hormonal influence

During the follicular phase, a specific hormone known as follicle stimulating hormone (FSH) is secreted by your pituitary gland. This tiny, pea-sized powerhouse, which is also known as the master gland, is found at the base of your brain. It secretes around 8 hormones that help to regulate a wide range of body systems.

The other important hormones—estrogen, progesterone and luteinizing hormone—are all fairly low at this point, but as you get closer to day 10 of your cycle, your estrogen level will begin to rise.

Estrogen is produced from your ovarian follicles. Its role is to feedback information to the pituitary gland to produce luteinizing hormone. The follicular phase ends when the level of luteinizing hormone peaks and the egg is released from the ovary.

Of course, you won’t be aware of all this messaging going back and forward between your brain and your ovaries. Other than a little relief that your period is over, you’re unlikely to be preoccupied by the intricacies of your hormones. However, if this is the month you are planning to conceive having some understanding of the science behind conception will help you to maximize your chances of becoming pregnant.

Planning conception

Contrary to public opinion, conception is not a simple process. Many couples who want to have a baby need to invest a little time thinking about when to have intercourse. This helps in order to coincide a little bedroom activity with the days around when the woman is likely to be ovulating.

I feel something...

Just before ovulation occurs, the follicle which contains the maturing egg pushes itself towards the surface of the ovary. The follicle looks like a little nodule or cyst and bulges just underneath the outer layer of the ovary. This can cause localized discomfort for some women who, over years of ovulation each month, become very sensitive to their body’s signals that they are about to ovulate.

The best time to conceive

If you are eager to conceive this month, don’t wait until you have already ovulated to begin trying. By the end of this week, you are likely to be coming into your most fertile phase. The window of time for this is around 5 days before actual ovulation and up to a day afterwards.

Sperm have a much higher lifespan than the average egg. They are still viable for up to 5 days after they have been ejaculated and they are inside a woman. Sperm can lie patiently in wait, just biding their time to make their move on an unsuspecting egg.

The information of this article has been reviewed by nursing experts of the Association of Women’s Health, Obstetric, & Neonatal Nurses (AWHONN). The content should not substitute medical advice from your personal healthcare provider. Please consult your healthcare provider for recommendations/diagnosis or treatment. For more advice from AWHONN nurses, visit Healthy Mom&Baby at