Hello doctor, my gf has ureaplasma parvum and is going to take antibiotics. we don't want her to infect me and have me reinfect her during this time.

Condoms : Have yourself checked for Ureaplasma if your Urine Analysis demonstrates Pyuria. Use condoms for sex in the meantime.

U parvum is normal: Disregard the test result and refuse treatment. Ureaplasma parvum is a normal bacteria. It is often present in the normal genital tract. You probably already have it. There is no need for either you or your gf to be treated for this. (In fact, STD experts never test for U. parvum. Also not for U. urealyticum, which also usually is normal and harmless.)

Doctors instructions: Ureaplasm parvum is a hard to diagnose infection. If your doctor diagnosed it and felt that treatment was warranted then you can simply avoid intercourse until the doctor has cleared you to resume your regular sexual activity.