Why are my periods irregular after stopping the pill?

Bottom linePeriods are often irregular after stopping the pill because the pill replaced your natural cycle rather than regulating it; most people ovulate within 1 to 3 months (up to 12 months after the injection) and the first few cycles can be long, short, or spotty, but if no period has arrived 3 months after stopping, an underlying cause such as PCOS/PMOS, a thyroid problem, high prolactin, or low body weight is more likely and worth a GP visit.

Because the pill was never regulating your cycle - it was replacing it. The monthly bleed on the pill is a withdrawal bleed timed by the pill-free days, not a period. When you stop, your own hormone cycle has to restart, and the first few cycles are often irregular.

What is normal

• Most people ovulate within 1 to 3 months of stopping the combined pill, patch, ring, implant, or hormonal IUD
• The contraceptive injection is the exception: ovulation can take up to 12 months to return
• The first two or three cycles are commonly long, short, or accompanied by spotting
• Symptoms the pill was masking - acne, heavy flow, cramps, PMS - may reappear

When it is not the pill

If periods have not returned 3 months after stopping, the pill is unlikely to be the reason. So-called post-pill amenorrhoea usually turns out to be an underlying condition the pill was hiding: PCOS/PMOS, a thyroid problem, high prolactin, or low body weight or heavy training. That is worth a GP visit and the standard blood tests.

Remember that you can conceive in the first cycle after stopping, before a period arrives, if that matters to your plans.

See tracking your cycle on birth control and the full guide to irregular periods.

Femora tracks your cycles as they return so you can see when a pattern settles - or when it does not.