Don’t worry. You are not the only woman who has to go pee after having intercourse. In fact, it’s quite normal. You just had a great orgasm (or two or three) and your body is still reacting. During orgasm, it may feel as if every muscle in your body is tightening and contracting. Sometimes your bladder gets in on the act and spasms as well, which makes you feel like you have to pee. Bladder spasms aren’t dangerous, just a physiological reaction to orgasm. It doesn’t mean you’re going to pee the bed, it’s just pressure from the spasm causing the urge to urinate.
Uterine contractions also can make you feel the need to pee. It’s common for the uterine to contract during orgasm and because it lies directly next to the bladder, those contractions can jiggle the bladder. Orgasm also causes engorgement from extra blood flow in the bladder/uterine neighborhood and that increases the pressure on the bladder. The bladder is super sensitive and reacts to pressure by sending a signal to your brain that it needs to release the pressure by peeing. That’s why you may wonder "why do I have to pee after sex pee".