Is a 35-day cycle normal?

What a 35-day cycle means

A 35-day cycle means 35 days from the first day of one period to the first day of the next. Most of the extra length, compared with 28 days, comes from a longer follicular phase: it simply takes your body longer to grow a follicle to the point of ovulation. The luteal phase after ovulation usually stays around 12 to 14 days. See how long the follicular phase is.

These are estimates. Use our ovulation calculator with your own average, and see when you ovulate for more.

Common reasons for long cycles

• Your natural pattern: some people consistently have 33 to 35-day cycles, and that's healthy.
• The teenage years: cycles are often longer and more variable in the first few years after periods start.
• PCOS: a common cause of long or irregular cycles, often with acne or extra hair growth.
• Stress, illness or travel: can delay ovulation in a single cycle.
• Low energy availability: under-eating or intense training can lengthen cycles or stop them.
• Thyroid problems and high prolactin.
• Coming off hormonal birth control or breastfeeding.
• Late perimenopause: cycles often lengthen, with gaps of 60 days or more near the end.

Long cycles and fertility

A regular 35-day cycle is usually ovulatory and doesn't reduce fertility. You just ovulate later, so timing based on a 28-day assumption can miss the window. If cycles are long and unpredictable, ovulation may not be happening every month, which is worth discussing with a doctor if you're trying to conceive. See long menstrual cycles.

Long cycles and mood

A longer follicular phase can mean more of the steady, brighter days many people feel before ovulation, and PMS arriving later than apps assume. If your app expects your period on day 28, you may feel PMS is dragging on, when your luteal phase simply started later. Tracking your real cycle helps line up the mood pattern too.