Met him on Tinder

Please be honest.... so I met this guy on August 7th and he well is insanely sweet and we get along so well, he asked me to be his girlfriend a day after I met his mom. And today I'm meeting his older sister and babysitting with him. Me and him have been sleeping over at each other's places and now I have extra toothbrush and underwear at his place and he has extra toothbrush at my place. Are we going to fast? My friends say we are going a little fast and told me not to get engaged yet.... (hopefully) can't get engaged yet.... freaks me out. We are both 21