Online dating

I met this guy online. Thursday. We chatted and texted a day before deciding to meet and greet. Conversations were great over the phone. Saturday we met and even when we met the chemistry was there. We talked about meeting up again this week. He does work crazy long hours. But now I hardly hear from him. Even though its only been a day or two since we met.... Should I move on, ask him is he interested or not, or should I just give him space and time? I don't want to come across as needy or seeking attention.