What would cause pelvic pain right after sex?

Not normal. Occasional pain with intercourse is common. Persistent pain during or after intercourse is not normal and a pelvic ultrasound, gynecologic exam and perhaps a laparoscopy.
Pelvic pain. Pelvic pain with sex is called dyspareunia.It is often caused by inflammation of pelvic organs-also popularly called pid.This can be dangerous as it can cause blockage of the fallopian tubes.Another reason is a condition called endometriosis which can be an additional cause for infertility.It is important to get medical help.