My period has not come on at all since July but I have taken 2 pregnancy test and went to the doctor and they all came up negative but that was around the first of September, and I have had some symptoms of pregnancy, but not the usual symptoms like sore breast and nausea could I still be pregnant? I need some adive PLEASE HELP ME.........IM ONLY 18 AND I NEED SOME ADVICE PLEASE!!!!!!!!!