Am I the red flag??

So my bf rn, we’ve been “official/exclusive” for about 3 weeks now. We met for beginning of June and we hit it off really well right away. And while we haven’t been together very long, I feel like we have been together for like a year or more which wild. We haven’t even met each other friends or family because well we just got together. But I feel like he’s been my bf for so long.

I’m asking if I’m the red flag because I’ve seen people say that if a guy rushes things and stuff like that then it’s a red flag. I don’t think I’m rushing anything but I definitely act like I have known him for so long. I’m weirdly comfortable around him.

The last relationship a couple years ago I was in was 4 years long so I got used to that dynamic. I’ve dated casually since and had fwb etc but this is my first actual relationship since my ex of 4 years. So idk maybe some left over reflexes of how to behave in a relationship are coming off of how I was 4 years in???

Idk if that makes sense. I’m over my ex but I feel like since it is my first relationship since then, that I wouldn’t be surprised if my brain kinda just fell back on it’s relationship default setting lol. Idk if any of this makes sense