Are we moving too fast?

I’m 18 and my boyfriend is 20. We’ve been together 4 months (a lot of it long distance because of covid-19 and his university commitments) I love him and can’t picture myself with anyone else but we’re already planning our lives together. He wants to be married within 5 years and is keen for us to have kids soon after. I know a lot of guys say stuff like this to keep girls interested but I can tell his heart’s in it for the long run. i’m freaking out tho idk