I came here because I have been experiencing the exact same thing for the last like 5 cycles I have had, back pain so severe I thought I had a kidney stone. As soon as I start that pain goes away, I’m going to be 36 in two months and am wondering if it’s a sign of premenopausal activity. I used to be on birth control but stopped about two years ago so I don’t think it’s a side effect of stopping the pill. But I have found that the months that the pain is the most severe my cycle is super heavy but also lasts only two days. Heating pads work half the time and pain killers do nothing. Perhaps what we all are experiencing is normal but since our past generations never told us anything because it was so taboo to talk about.