I think i have a UTI

I'm 15 and I had sex on Wednesday which was one of the last days of my period. I didn't pee after because I'm dumb and no one told me that was like a thing.... I told my boyfriend's mom and that's basically how she found out we've done it but she was really cool about it. My mom's at work so I texted her asking to call me when she gets a chance... Any tips besides cranberry juice?

Edit: I went to the doctors today and it is a UTI. I got antibiotics that I need to take for the next 5 days then I'm good... Also I've been chugging cranberry juice which is the nastiest shit ever.