help!

So me and my boyfriend have sex quite often it is something we have always been open to each other about and enjoy doing. I am on birth control and we use condoms but when We run out we still have sex and make sure I take my pill on time and that he pulls out. I am on a birth control that stops my period so I do not have one and I've had cramps for a while and have had some symptoms of pregnancy however I don't know how I am supposed to tell with not having my periods. I took a test and it said negative but I'm still not sure if it could be wrong. What should I do? Am I just over thinking?