My advice has always been that if it feels wrong, it is wrong. Anything needs to work for both of you and if you feel he is going too fast then it's wrong for you.

If he is genuine, tell him you need more time and he will give it to you. If you tell him and he starts to put pressure on you or tells you "A real sub would" then block him from whatever communication tool you are using and move on.

I once met someone after 2 weeks and I considered that to be a rush, generally I'd want to talk to someone until I knew we had more in common that just a kink and a surge of endorphins from meeting someone new. Usually for me its at least a month, usually more.