Im on Lo loestrin fe birth control that I take everyday that I've been taking for a year . I recently found out that I had strep throat and I'm taking penicillin. I had protected sex and I've been having some sharp pains in my stomach for the past few days. I do continue to take my medication and birth control. Am I having pain because we did it too rough or because I ate before? My last period was May 17. I recently just start having sex this year and this is my third time having sex with The same guy.