I am 17 years old and I have missed my period for 12 days no spotting no period at all. I have had headaches, heart burn and nausea with and without throwing up. I took one test when I was about 7 days late and it didn't show positive or negative, it was blank. I took another test at 12 days late which is today and it came out negative. I don't know why but I feel like I am pregnant. I don't feel like I'm under stress or worried about getting my period I knew that by having sex I could get pregnant so if I am I wouldn't be surprised. When should I test again . Both test I took were not morning urine.