See a hematologist. If your periods are heavy, they may recommend birth control to limit bleeding. It may also be a good idea to see your hematologist the week before your periods start so that your blood counts can be checked. It may be hard to predict when that is, but keep it on a calendar to see if you can start to predict it. You need to take pain medicine during your cycles on a regular basis.
Very little. With sickle cell you are already anemic, and if your hemoglobin drops any during menstruation then that can bring on "mini-crisis" or even a crisis. Things that increase circulation is really the only help if your pain is actually extra pain due to sickle cell. Rest to decrease o2 demand, heat to dilate your blood vessels, extra Niacin and folic acid, plenty of fluids, nsaids like ibuprofen. Drj.