Waking up screaming??

For the past few weeks, my little boy has been waking from his sleep screaming, takes a good 10 mins to calm him. He's doing it during the night and with his naps.

He also is an early riser. So we are exhausted. I've gave him stuff to help teething etc however I don't think it's that, usually his cheeks go bright red when he's teething and they haven't been at all this time.

I'm unsure what it is or how to stop this?