hi, i missed my period for almost three weeks, i did about 7 urine HGC and all of them were negative, a gynecologist doctor check me and did ultra sound , and said i have a lot of fluid but the pregnancy did not appear and she ask me to come back after 8 days, i did pregnancy test 3 days later and also was negative but now i m suffering in the house from bad back abdominal pain , fever and weakness. i just want to know whats my problem??