Am I overthinking things? (22F)

I've been talking to this guy (24M) on Hinge for a week now. We have quite a lot of things in common, the conversations flow well and we both ask a lot of questions about eachother ect. He's even asked to see me once quarantine is over and we have an idea of what we'll do when the time comes.

But I feel like he's losing interest. I know, I know, it's only been a week and it's still quite early on but I can't help but feel like this.

At first he'd respond quickly and we'd have a back and forth conversation throughout the day – now he's still talking during the day, still holding the conversation but his replies have become longer. He takes a few hours to reply.

Normally I'd think nothing of it beyond the other person may be busy/working/socialising with others/doing hobbies ect, but I'm not too sure why I'm suddenly thinking otherwise..

I just wanted other people's perspectives. Am I overthinking things or is this a natural progression?

Thanks.