UTI advise

Hey ladies! I'm 20 years old and I haven't had my period since may. I am sexually active, but I am not pregnant. Last night I knew as soon as it hit me I had a UTI my fiancée went to Walmart and got me Azo, parsley, and cranberry juice. I started bleeding really bad but couldn't tell if it was a period or I was peeing blood. My doctor put me on progesterone. I have miscarried and my period has always been messed up. These are the reasons he put me on it. I was just wondering if anyone has had anything like this. It's like excruciating pain. We are getting married next month and want to start trying to have a baby and I was wondering if anyone had any advice for that as well.