In the build-up phase, also follicle (maturation) phase, preovulation phase or proliferation phase, the egg cell matures.

The hypothalamus signals the pituitary gland to send follicle-stimulating hormone (FSH) to the ovaries in order for them to prepare the release of another egg. In preparation for this several follicles begin to swell. Estrogen increases to thicken the lining of the uterus so that it can host an egg.

During this phase your physical energy increases. You may even feel restless at times. Initially there is little to no vaginal secretions, then they begin to increase. Cervical mucus appears yellow or white in colour and is usually sticky in texture.

The hormones FSH (follicle stimulating hormone) and LH (luteinising hormone) cause the growth and development of the liquid-filled follicle in the ovary in the first half of the cycle and the maturation of the egg cell in it.

The follicular phase is often the longest part of the menstrual cycle with an average length of 16 days. It can however, last anywhere from 11 to 27 days depending on your cycle.

Having a long follicular phase?

A longer follicular phase means that it takes more time for your body to ovulate. Using hormonal birth control for a long time can lengthen your follicular phase. Low vitamin D levels have also been linked to a longer follicular phase.

Physiological variations in menstrual cycle length are mainly due to variations in the length of the follicular phase. The time of ovulation shifts depending on the length of this phase. In 50% of cycles, ovulation occurs after the 14th day of the cycle, which is due to a longer follicular phase. In 5% of the cycles, this phase is much shorter and ovulation takes place before day 12 of the cycle.

Having a short follicular phase?

Having a very short follicular phase could negatively impact your likelihood of conceiving. When a follicle ripens too quickly, the egg inside that follicle may not be mature enough or ready to be fertilized. This can make pregnancy more unlikely to occur.

breathe ilo helps you to learn where you are in your cycle. That way, you can get to know your body better and understand your unique cycle ♡