Cortisone and disrupted menstrual cycle?

38 female. 120lbs. 5’5”. No major medial issues. No medications other than cortisone shots for pain.

Can having a cortisone shot cause prolonged menstrual bleeding and distrusted cycles? My sister had a few cortisone shots to her neck area due to pinched nerves. Since then her last period was heavier than normal, stopped on time, but then a few days later she started having light brownish spotting that is going on for three weeks now. Her last ob appointment was normal pap.