help with uti?!?! help!!!

So I had a uti about a month or so ago. I went to the doctor, they gave my an antibiotic called amoxicillin, for 5 days. I also take birthcontrol pills (don't know if that matters) but I made sure I didn't have sex or had sex with a condom while taking it. The infection went away for a while but now I have it again I believe. I haven't went to the doctor yet, but I've been taking azo. Another thing too, my mom has amoxicillin from a tooth ache left over, a lot of it. Couldn't I just take that again like how I did before instead of going to the doctor? Aren't they just going to tell me the same thing? Please help, I need advice as ofwhat to do. This is causing me a great deal of pain and it is horrible. Is there anything other than antibiotics?