I stopped birth control a month ago after being on it for 7 years. i am now on day 31 of my cycle with no period; however i have been having pelvic and menstrual cramps that started on and off last week. ive taken 3 pregnancy tests and all say neg. ?

Tests are accurate: Today's home pregnancy tests are very accurate and not affected by foods, herbs, common illnesses, sexually transmitted diseases, vaginal spotting, or medications. A test gives a reliable result 3 weeks after sex (or when conception might have happened) or 1 week after missing a period. If done sooner, a negative result may be due to testing too early, such as less than 2 weeks after conception.