I Have Brown Discharge For A Day, Kindly Suggest

hi. im 18. i was ment to start my period like a week ago , but it never did cum. i only had slight cramps a few days ago. but that came and left I started gettin brownish discharge yesterday ,like how i might normally get when my period is ending. i dont have any other pregnancy symptoms like soar breast or anything. i did have unprotected sex . but that was about 4 days after my last period finishd. so i cudnt have been ovulating then. so im wondering wat the reason for the little brown discharge cud be. it was slightly stronger yesterday than today . today theres nothing left . nd i dont have cramps like i usually do when im startin my period. am i ok? i dont wanna scare myself thinking im ill. thank u.