Hi, for the past 3 weeks I have been having abdominal pain and pain my lower back, today I bleeding from my vagina , it s not my period as my period ended last week. I also feel sick to my stomach and am getting hold and cold. I went to the doctors and he has given me a 3 day course of antibiotics to kill bacteria if the yeinary track....please tell me what is wrong? thus has happened since I had sex with a new partner and Ivan petrified, I ve had STD checks and they re all negative