You may have a urinary tract infection causing pelvic pressure and pain. (doctor-info.website)
You may notice more pelvic pressure as well since baby is lower and now pressing in that area. (metrodetroitdoulaservices.com)
Even if you're not noticing leakage or strong urges to pee during sex, you still may need to do Kegels if you're feeling uncomfortable pelvic pressure in general. (romper.com)