Bladder infection?!

Bladder infection?

could someone help me out?! i'm so tired of getting bladder infections (urinary tract infections)
i started getting them when i was about 7, and i got them consistantly until i was about 12. at one point, my doctor told my mother i had twisted ureters, but i never heard anything else about it again, would that have an effect?
i stopped getting them for a while, and then when i got to college and started having sex they came back.
i'm at the point where i get one about every 3 weeks, some aren't bad, and i just drink water and take cranberry pills for a few days, but some get to the point where i pee blood and can't stand. i'm allergic to sulfa drugs, so i can only take certain anti-biotics, but anti-biotics also mess with my birthcontrol
as you can probably guess, i'm getting really tired of this, so is there any option other than being celebate or going to the doctor and taking anti-biotics every month? am i just a freak?

I had the same problem for awhile, then my doctor told me that it was probably happening from sex. So right after sex I make sure that I pee and I also clean my "area" with a cotton ball and a little rubbing alcohol. It will burn a little, but I don't get infections anymore.