I had unprotected sex on 11 dec 2017 after that i had taken unwanted pill 1 hour after having sex on that month my period came 4 days earlier from regular date but my blood flow was little less then the regular blood flow in next month my periods came 5 days earlier then also the blood flow was little less then the regular i had home pregnancy test both month but it was negative some time i faces back pain stomach pain which are the early symptoms of pregmancy i am 20 year old plzz suggest me .