Phases of your cycle

Phases of your cycle

The menstrual cycle can be divided into four phases:

  1. Your period
  2. The follicular phase or the first half of your cycle before ovulation
  3. Ovulation
  4. The Luteal phase or the second half of your cycle after ovulation

The follicular or the first half of your cycle may from cycle to cycle and from woman to woman. It is this phase that determines the cycle length.

The luteal phase length (the second half of your cycle after ovulation) is constant, rarely changing by more than a day or two from cycle to cycle for the same woman. The luteal phase usually lasts from 12 to 14 days but may last from 10 to 16 days. The best time to conceive is just before and during ovulation.

Cycle Phases

Menses is your period or menstruation. You are generally not fertile during this time. 

The follicular phase goes from the beginning of the cycle until you ovulate. The hormone estrogen dominates this phase laying down your endometrium (lining). During this phase follicles (with eggs inside) begin to develop and mature and your body prepares for ovulation. One follicle becomes dominant ready for ovulation. The length of this phase can vary from woman to woman and from cycle to cycle. You are most fertile at the end of this phase during the days just before and including ovulation. 

Ovulation is then triggered by a surge of luteinizing hormone (LH), the ovarian follicle ruptures and releases the ovum (egg) which can then be fertilized.

Next is the luteal phase. This is the time from ovulation until the end of your cycle. If you conceive in this cycle the fertilized egg will implant in your uterine lining roughly 7 to 10 days into this phase. If there is no conception the uterine lining will shed (this is your period), and your body will begin to prepare for a new cycle. The luteal phase usually lasts 12 to 14 days but can last between 10 to 16 days. Progesterone is the hormone that dominates this phase. If you become pregnant progesterone keeps rising and it helps to maintain your uterine lining throughout pregnancy