I think I'm 5weeks Prego but no positive urine test

Having a ton of symptoms! Nausea, dry heaving when I brush my teeth, cramping, excessive burping, gas, can't stand the smell of certain things, mood swings, headaches, unquenchable thirst, indigestion & forgetting a lot.  And I have taken maybe 7 home pregnancy tests & one at the doctors office, all negative!  And same thing happen to me a few months ago when I had a miscarriage bc I continued to drink and have fun bc everything said negative, doc won't take blood for another week, but I read that it may be because I'm over weight and the hormones take longer to show up on at home tests. Has this ever happen to any one?? I'm uncertain & have stopped drinking and have been taking prenatal soft the past 3 months. Anybody have any advice?