Cramps, no AF

Ma

AF is due today/tomorrow. I’ve had cramping for nearly 4 days, yesterday was particularly awful, just a dull cramp in my left side that lasted all day. Today I have no cramps at all, which is weird, and I still haven’t started. This morning I got a negative pregnant test. I just had an HSG done and some say that can mess with your period. Has anyone had anything similar happen to them?