We've been on 4 dates but I haven't heard from him in 5 days.. Is it over?

I think it's over. If you already had with him it makes him think less of you. I know it sucks but that's how guys are and that's what they care about. You already gave it up so hes probably out looking for the next young girl. You'll be ok tho just learn from this and next time don't give it up so fast. Guys like a challenge