Most Helpful Guy
It is reasonable in the beginning of seeing someone. Some people like to move ahead slowly in the beginning. I'd send him a text every few days to say hi. If you don't hear from him within a week or two, move on.
Most Helpful Girl
I don't think it means he has lost interest. Has he been in touch via text daily previously? Two days is really not a long time, but if he usually sends 20 texts/day then I can understand why you might be a bit worried.