Okay so, I was on birth control (the shot) since 2016. I got it in April 2016, then July 2016. I stopped then got back on it in March 2017 then stopped and got on it March 2018. 3 days before I got back on it, I had unprotected sex and he saw little bit of white stuff but we didn’t know if it was my cum or his so that made me get back on birth control, my doctor told me to take a test 2 weeks after the birth control just in case, I took one last Wednesday and it was negative. In 2 days I’m supposed to get my period and I have this pinching feeling in my lower stomach and it hurts every time I stretch. What can it be?