Brown discharge and no periods

Chetna

I had unprotected sex on 21 January after that i took unwanted 72 on 23 January…now since 9 February i am saying few brown discharge like 1 drop in a whole day my periods date was 10 February, i took pregnancy test on 10th February it was negative Today also i did another test it is also negative but I did get my periods please anyone can suggest what i will go i am too worried…