The last i had sex was three months ago. since then I have felt very sick and nauseas. I have taken several home pregnancy tests and two blood pregnancy tests, all with negative results. I also had my menstrual cycle each month, each one varying in length and severity. For some reason I no longer have really painful cramps, just mild ones. my question is how reliable are those kinds of tests? Or am i just paranoid?

Urine or blood hCG (human chorionic gonadotropin) tests are routinely ordered 10 or more days after a missed period. The sensitivity of for over the counter urine hCG pregnancy tests varies between 90-97%. Blood hcg tests are more sensitive at 97-99% and they can actually quantify the amount of hCG circulating in the blood. Depending on the test, levels between 20 to 100 mIU/ml of hCG is considered positive for pregnancy. Since you have had both and you are continuing to have your period, it is highly unlikely that you are pregnant.