I had sex on 4th feb. again on 18 feb i had unprotected sex but i took unwanted 72 within 48 hrs. my period date was 18feb which didt statred. i had took test on 23rd it was negative. i got my periods on 25th feb which was light n brown or black but on nxt day no period in morning,again it started in evening with little n brown. 3rd day it was still little and black or brown. why ths happen? and i took test today in morng it was negative... whn shld i tk test again? wat is reson for brown clr or light red dnt no? is ths withdrawal bleeding? whn my periods wl come? am i pregnant? reply as soon as possible .