Post flop situation that is throwing me off(leak)

[Cowy]

Heres the situation, there is a PF limper and you raise....they flat call. Or it could even be one of the blinds that calls your raise, what is important here is that you are in position on them.

The flop comes, and they bet into you rather than waiting for your cbet.

I never know how to interpet this.

If it is a textured board, I.E there is a possible straight draw or flush draw, this brings another element into it.

But what if it is a nontextured board, if they were really that strong, wouldn't they wait for your cbet to check raise?

This move completely messes me up a lot.