I had sex yesterday but i feel real pain when trying to empty my bladder, could that be because my pid wasn't treated well or it's just a bladder infection? i finished a course of antibiotics and i waited a week before having sex. why do i feel pain?

This partly duplicates your previous question. In that one, you said nothing about how long since your PID diagnosis. With this new information, it seems likely you still have PID or perhaps a pelvic abscess. Get medical care in person immediately. Good luck.

It is too early to differentiate those 2 problems at this time. If urine appears turbid with bad smell, burning pain during voiding and frequent urge (dysuria) then bladder infection is suspected, especially yeast infection because you were taking antibiotic. Other than that, persistent PID may still be present. Please see your doctor if symptom persists with sex abstinence in the meantime.