Okay so I'm 15 days late on my period and I've taken 5 different pregnancy test and I've gotten 2 negatives, 2 invalids, and 1 faint positive and I went to my local health clinic and I was put on prenatal vitamins and given a pregnancy packet. I was just wondering if I could still be pregnant? I've been nauseated, heartburn, frequently urinating. I'm really confused since I had a negative test result with them. Should I retest or wait it out?