Irregular periods.

I have had my period three times this month and the last two were normal and I’m usually never in pain but I just started treatment for a UTI and when I had gone to the bathroom this morning I wasn’t bleeding and as soon as I sat down after going pee blood literally just started coming out and now I can’t drive anywhere because I get way to nauseous and have to pull over. But anyways, I don’t know what is causing me to have my period so often this month of what could be causing this amount of pain.