hello i am 22 years old 5`1 and 227lbs this is the first time i been this heavy i have been having unprotected sex for almost a year my medical history is okay just a few UTI`s in the past. Recently when i brush my tongue while brushing my teeth i throw up this yellow liquid which never happened to me before except when i was pregnant in the past can this be a possibility that i can be pregnant?? I mean my period would come but only last two or three days i would take a pregnancy test but all of them are negative but this is the same thing that happen last time and i found out i was 3 months pregnant please help...