Had unprotected sex 8/29, got period 9/2, began experiencing mild pelvic cramps, brown discharge 9/27. is pregnancy likely?

Check pg test.: If you have not had sex since 8/29, do a home pg test to know for sure. Follow the instructions exactly. Be sure the kit has not expired. If you have not been in a long term (1 year) mutually monogamous relationship with negative testing for stds for both of you, get checked for sexually transmitted diseases, which can cause pain and/or discharge.