Suggest Treatment For Heartburn,dizziness Ans Nausea

hi i am a month and 5 days late with my period and i think im pregnant i have a lot of the signs i have heartburn a lot more i also get nausea at night but i don't throw up i have been getting major headache and dizziness almost to where i want to pass out which i have never had that bad i have taken 5 pragnancy tests 2 the doctors did and a blood test but they all came back nagitive. i have heard of a thing where no tests come back positive and then on the due date the mother freaks out cause all the doctors and the tests said she was not with child. is there any way i could be one of them mothers and if so is there any way for me to get doctor appointments to make sure my baby is heathy?