* Ovulation: You can get pregnant any time in the week leading up to ovulation, and up to a few days after ovulation. This means it's possible to have your period one day and ovulate a few days later.
* Short Cycles: Some people have shorter menstrual cycles, meaning they have a period for only a day or two. This can make it easier to ovulate earlier in the cycle.
* Spotting: Sometimes, what you think is a period could be spotting, which is light bleeding that can occur outside of a regular period. It's common during pregnancy, and it could be confused with a period.
The Bottom Line: If you are sexually active and worried about pregnancy, it's always best to use reliable contraception or talk to your doctor about your concerns.