ive been on the depo injection since october2007. but in march this year my partner came home and we had sex but a week later i had another injection of depo. but now ive been feeling like bubbles popping in my womb area. and i am also going to the toilet alot. i have done pregnancy tests, but everytime i have done them they keep saying negative. but i dont normally feel like this when if had a my injection. so could somebody please help me. because i am in a dilema with not knowing what to do.