Pelvic pressure and light cramping after sex

​I have had a recent change in the past two months, during sex  i have been experiencing unusual pelvic pressure in my uterus some times the presure last days after intercorse and even makes me feel a need to urinate often.it is not painful just odd I am not pregnant and do not have a UTI. Also notice light cramping after sex. Has anyone else ever noticed symptoms like this?i am planing on seeing my obgyno the end of the month.if you have any in sight  please share thanks.