Painful coxis when I run

[Deleted User]

Hi when I started running on the treadmill on sunday, I got a achey, niggly pain in my coxis. Probably should have stopped, but kept going and after 10mins or so it wasnt painful. However, just running around playing football with my son yesterday & today and its still painful. Any ideas why? thanks

Screamapillar

Coccyx?