Is cramping after orgasm and early sign of pregnancy? I have had all the symptoms and am about a week late for my period

Do a home test. If you have been having unprotected intercourse, you could be pregnant. You can resolve the matter with a home pregnancy test.
Probably not. Anything that makes your uterus sore can cause cramping, with or without an orgasm. Infections are common. So is endometriosis. If the problem continues, go see your family doctor.