Are we moving too fast?

So I met this guy a week ago today and in that week, we went on a date, became a couple, met each other’s parents & even had sex. We’re both in our 20’s so it’s not like we’re high school children and we don’t think it’s too fast because it just feels right. We like each other a lot and it doesn’t feel like we’re rushing into things. However, some people have voiced their concerns that we’re rushing into things, that we’re gonna fizzle out soon, & that we’re gonna get hurt. I need some advice because it seems like even my own mother is against us being together. Please help :(