Running Cramps

Does anyone else get cramps in their lower stomach while running?? Do you know why? I started taking magnesium supplements as I heard they are good for cramping and so far they haven’t done anything. I honestly thought my period had started while I was running today (it’s due which is probably why the pain was worse) but it hadn’t started. It was the sharpest pain and only lasted about 15mins. I get this every time I go for a run. Anyone got any advice on how to prevent it or know why it could be happening?