Confused (longish story)

So I’ve been talking to this guy for about a month, and he initiated the whole thing. He added me on snap (we went to school together lol) but then messaged me and I wasn’t really interested so didn’t talk much. About a week later he swiped up on my story and said “you’re cute (:” and from there we started talking, and it turns out my best friend is close friends w his best friend and so she was like yeah go for it!! And he was like “here just text me instead” and gave me his number and so we continued talking, but his replies started getting slower (anywhere from an hour-8+) but he still seemed interested. We had a really good convo a week ago but after that he’s been messaging less and taking longer to reply, and we’ve gone 2 whole days w out messaging. I like him, and I thought oh maybe I should start the convo since he did it most of the time, but now I just feel annoying. But I’m confused because I messaged him yesterday around 1 and he answered at about 8 and put a (: in his reply? This is really long lol but idk, how should I go about asking about his late replies or is it even worth it? Does it sound like he’s uninterested? Tia :)