What kinda bug is this??

Looks like a thrip to me. They can be a pain in the ass.. even if you don’t see others they are likely there. I’d begin some type of pest management regimen to exterminate any others and be sure no more populate your grow area. There’s plenty of natural pest management solutions you can use, especially since you’re not in flower yet. I have used dr zymes which was decent but prefer Green Cleaner. I’d be proactive with it, because if they stick around into flower it’s a whole nother beast in my opinion. Odds are what you saw the other day is not the same one you saw and caught today.. so there’s likely more. If there’s no physical damage to leaves yet than you’re in good shape but still recommend starting a preventative pest management regimen.