Is it normal to poop a lot before getting your cycle?

Yes, in some women. Various bowel movement changes happen throughout the menstrual cycle, related to the different levels of various hormones. The prostaglandins, chemicals the body makes that also cause the uterine muscle contractions during periods, can cause intestinal spasms. This can result in gassiness and an increased number of bowel movements. A primary care or ob-gyn doctor can help with relieving symptoms.