With flu season right around the corner, this is a great question. I've never heard of this happening before nor has it happened to me, so I would definitely check with your healthcare provider and don't forget to see what our health expert, Molly O'Shea, has to say.
When I’ve gotten the flu shot in the past, I’ve had no side effects. (Lucky me!) I do know some people who have had aches and even a low-grade fever after getting the flu shot. I had never heard of any period-related side effects of the flu shot so I checked WebMD and the CDC. I don’t see any information about the flu shot delaying menstruation. Be sure to check our health expert’s answer, too.
Nope. The flu shot shouldn’t affect your hormones and doesn’t make you sick -- so it can’t delay your period. Something else is the culprit if your period is overdue.
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