I'd say there is a huge chance it's his teeth. Unfortunately, this can cause sleep disturbance for weeks on end - 6 weeks for my DD when she cut her first two teeth. Was a nightmare.

But the good news is it never lasts and he will be sleeping through again before you know it.

I don't think there's ever been a baby who sleeps well all the time. They all have their little ups and downs and phases, but they always pass!

Hang in there!