Hello,
Thanks for writing to us.
Urination immediately after sexual intercourse can help to reduce chance of urinary infection. However, I suggest you to undergo one routine urine examination to rule out UTI as per above clinical presentation.
If your bladder is entirely empty before sex, then chances are that the sensation of having to urinate has more to do with pressure on your bladder, or potentially a precursor to ejaculation.
Also, if your bladder is empty, then you know that if any fluid does come out of your
urethra during early or late orgasm is not urine. It is similar to male type ejaculation, seen among women during orgasm.
Urinating after sex is also a good idea, because it flushes out any bacteria from your urethra. Review with test report.
Hope, it helps for your information. Good luck and take care.