Does anyone else think they are a demigod?

Who knows. there are so many strange things in the world out there... Do you remember having any dreams on the matter? If you do, that could be interesting. But either way, there is no reason to rush. 13 is not an age in which things are very clear one way or another. Wait until you are 18, then you would know more about yourself to be confident in your powers, or lack of them. Good Luck either way.