So for 3 days i had lacrosse camp and we basically practice for 6 hours. Plus one hour but that was for break. It was the most i ever exercised so then 2 days later i got my period. It was on time the only thing that worried me was that it was just a little bit of blood. I never seen it begin light like that . I have back pain and cramps like i normally would have. its kind of getting heavier but slowly im very worried.