Why did my period stop?
Last updated September 3, 2026.
Pregnancy first - always - then the list sorts by circumstance, per OWH: breastfeeding, hormonal birth control (absent periods are expected on the shot, implant, hormonal IUD), perimenopause, low weight or hard training, stress, thyroid, PCOS. Three or more missed months is amenorrhea, and that is the workup line - the causes matter beyond the period: low estrogen erodes bone. Sudden stop with hot flashes under 40: ask about primary ovarian insufficiency specifically.
What to do
- Test for pregnancy first. The commonest cause, the cheapest rule-out.
- Check the birth control. Shot, implant, hormonal IUD: absent periods are the design.
- Three months absent: workup. Pregnancy, thyroid, prolactin - the hormone panel.
- Under 40 with hot flashes: say so. Primary ovarian insufficiency needs the specific question.
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