8 year old and bladder control

Donna • I'm 28- been with my partner a long time, we tried for 3 months and I'm now 16 weeks, due May 22nd 2016! Excited much!
Hi guys my 8 year old has suddenly started wetting himself again, it happened a wee or so ago he was playing but never noticed he'd dribbled, then yesterday he rushed to the loo but didn't make it, and this morning he woke with wet pants? Is this anything to worry about?