Am I overthinking? Or ami just jealous?

I guess I’ll start off in saying that this is my first relationship kinda so I really don’t know much about it but I’m trying really hard to figure everything out and be the best girlfriend I can be. On my birthday my boyfriend couldn’t come for some reason and I mean that’s fine, we can hang out another day. And I look later on snap and I see him hanging out with another girl that he fell asleep on FaceTime with her. I asked what he did all day and he lied to me about it and just told me he had work all day. I think I’m just more upset because we never do those things with me like at all. I don’t expect him to tell me what he does 24/7 I guess I was just hoping for maybe a little more attention or something..