Why am I bleeding between periods?

Bottom lineBleeding between periods is often harmless, caused by ovulation spotting, starting or missing hormonal birth control, or early-pregnancy implantation, but it can also stem from infections, polyps, fibroids, hormonal imbalance, or perimenopause; see a doctor if it is new, repeated, or unexplained, follows sex, comes with pain or unusual discharge, or occurs after menopause.

Light bleeding or spotting between periods (intermenstrual bleeding) is common and often harmless, but some causes need checking.

Common, usually harmless causes

• Ovulation spotting - light bleeding mid-cycle
• Starting hormonal birth control - breakthrough bleeding in the first few months
• Missed birth control pills
• Implantation - light spotting in early pregnancy

Causes worth checking

• Infections including STIs (chlamydia) or vaginal infections
• Polyps or fibroids
• Hormonal imbalance, PCOS/PMOS, or thyroid issues
• Perimenopause
• Rarely, cervical or uterine changes

When to see a doctor

• Bleeding between periods that is new, repeated, or unexplained
• Bleeding after sex
• Bleeding with pain, fever, or unusual discharge
• Any bleeding after menopause (always get this checked)

Spotting that lines up with ovulation or the start of birth control is usually fine. New, repeated, or post-menopausal bleeding should always be evaluated.

Track spotting against your cycle with the Ovulation Calculator to see if it matches ovulation.

Femora lets you log spotting and where it falls in your cycle, so you can tell ovulation spotting from something unexpected.