Help!!!

Hi everyone I have a question if anyone could help me, it’s quite embarrassing but I’m 17, I am sexually active but I am on the pill and use condoms, i keep getting UTI’s and they are very embarrassing to talk to my mum about and are really annoying and painful I know the antibiotics aren’t good for ur body so I hate having to keep taking them everytime I get one, I have one at the minute and have for the past week or two, I really dont know what I’m doing wrong can anyone help ???