u can have sex no matter what u are taking
Honestly you really should restrain from sex until your UTI is better as it could aggravate your infection. I would suggest waiting until at least the day after you're done taking your antibiotics.
Also if you're on birth control keep in mind that they react to antibiotics and are no longer as functional. So even after you're done taking the antibiotics it might be a good idea to use a back up form of b/c (aka condoms) for a couple weeks -especially if you don't want/can't handle an oops.