I am 10 years post menopausal and a few years ago I had a facet joint steroid injection at L5. Several days later it made me have a period for a week. The pain doctor recommended I go to my gynecologist as they hadn't heard of it before. After going gynecologist, getting an ultrasound, hysteroscopy and endometrial biopsy nothing was found. Better to be safe, but I believe as others have said it is a possible side effect.