I had unprotected sex the first day of my period, after i had sex my period came very light and two days later it stopped. could i be pregnant?

Maybe not. Do test.: It can be hard to tell if a woman is pregnant because some of the symptoms seen in early pregnancy can also happen in non-pregnant women. A urine pregnancy test gives a reliable result if done correctly. One can test about 3 weeks after sex (when conception might have occurred), or 1 week after missing a period. An ob-gyn doctor can evaluate any persistent or worrisome symptoms.