Worried For Brown Discharge After Unprotected Intercourse

Hi, im 16, i weight 107 and ive always been healthy i never had a problem but for the past maybe 3 or 4 weeks i been having brown stuff with clots coming out n i know it not my period cause i missed it the month before plus it doesnt fill my pad at all it just spots pritty much but its been goin on too long and im starting to get worried. Someone told me i might be pregnant, and maybe thats it, ive been having unprotected sex with my boyfriend and now i dont know what i have. Can i be pregnant?