What Causes Missed Period And Menstrual Cramping With History Of Bladder Infection?

Hi! I'm 38 and never been pregnant. I had a bladder infection, (1st time) and I had the worst strand of it where they had to change my prescription to a stronger meds. Afterwards, the first time I had an orgasm it hurt like menstraul cramps. Then I noticed I had a lingering pain on and off for a few weeks that was in the left side that felt like a mild menstraul cramps. So, I started my period and now I am only getting menstrual pains on the left side, same spot. I've been on Yaz for alittle over a year. I have an appt to see an OBYN next week but I am alittle worry. I don't have medical insurance so this is worrying me. What can it be?