I am 29, I have been diagnosed with PCOS, I just had an ear infection in which I was on amoxicillin for ten days. I don't have regular periods, I'm not on birth control or any medication other than my albuterol inhaler and I have been having severe lower back pain near my kidneys. When I urinate, there is bloody mucus/tissue in the toilet and sometimes when I wipe. This isn't the first time this has happened and I wasn't on any kind of medication then. It actually happens pretty frequently, sometimes without the back pain. What could be happening and is it serious enough to go to the ER?