Common, harmless causes
- Ovulation spotting - light bleeding mid-cycle as estrogen dips
- Starting or changing birth control - breakthrough bleeding in the first 3 months is normal
- Implantation - light spotting in early pregnancy
- The first years after menarche - cycles and hormones are still settling
Why it happens
Most spotting is hormonal: small shifts in estrogen and progesterone cause the lining to release a little blood between periods. Brown spotting is just older blood. On hormonal birth control, the lining is thinner and can shed unpredictably at first.
When spotting is a red flag
See a doctor if spotting is heavy or frequent, happens after sex, comes with pain, smells bad, or appears alongside unusual discharge. Bleeding after sex or persistent bleeding between periods should always be checked to rule out infection, polyps, or other causes.
What to track
Note when spotting happens (mid-cycle vs random), how much, the colour, and any triggers (sex, new pill). A clear pattern in your tracker helps your doctor pinpoint the cause quickly.