SHARP PAINS PLEASE HELP

So recently I went to the doctor with a pain in my back and it burned to pee along with nausea. They said it was a kidney infection no big deal. So I take my antibiotics as prescribed along with a birth control. As my kidney infection becomes clear a sharp pain develops in my lower right side and I find it hard to do anything I stopped taking the BC and Antibodies and the pain stopped after a few day and I got my period, on the last day of my period I had sex with my boyfriend and the next day took my birth control to start again? Now the pain is back and it’s just the same if not worse than before! I thought it was the antibiotics?? PLEASE HELP ME