Burns when i pee.

Its been maybe a week and I've noticed it slightly burns when I go pee.. I haven't noticed much else except that it smells a bit stronger then usual. but I'm just wondering what it could be from. I lost my vcard about a month ago and a half ago havnt had sex since that one time . My GrandmA thinks it's a kidney infection which sex can lead to. But I serious only had sex once. I don't know why I'm getting an infection..

Help? The only reason I'm asking this is because I don't want it to get bad where I need to go to the doctor. If its because of sex I don't want my mother to know that's why. But should I be worried? Anything to help it stop burning. ?