My period usually lasts 4 days i had it for 2 now getting brown discharge. i had unprotected sex about 2 weeks ago. could i be pregnant?

Yes: Any irregularity in periods with unprotected sex can be a sign of pregnancy.

Maybe...: 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.