I was barely having any bleeding last month, wasn't normal. i messed up my birthcontrol. i took a test it was negative, but could i be pregnant?

Maybe not...: 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.