If a guy doesn’t initiate conversation first, does it automatically mean he’s not interested?

I’ve got a crush on this guy in my college class. We share 3 classes together but he sits close to me in 1 of them while in the others he’s on the opposite side of the room. I get a bit shy initiating conversation first but did so because I’m interested in getting to know him and find him attractive. I’ve initiated 2 conversations so far. The second time, we talked for a good 15-20 minutes 1-1 and I learned a good deal about him while also discussing our classes. I find him interesting, pleasant to talk to, and it seemed like he also liked talking to me. He’s not done anything wrong, so I don’t want my post to appear like that’s what I’m implying.

I’m just not sure if I’d be beating a dead horse if the dynamic ends up becoming one where I always end up starting conversation first. Do guys not initiate first to cue “I’m not interested“?