Most Helpful Guy
Some guys are rubber bands. The more space you give him, the stronger he'll come back. You haven't heard from him in 4 days, I'd send him a text to say hi, and if he returns it, just take it from there. If you guys have gone 2-3 days without talking before, I'd hardly say that's chasing him.
Most Helpful Girl
Delete his number.
Delete all trace of his number off your phone.
If he contacts you within another day then respond.
If he contacts you after this then delete and ignore text (unless genuine reason - as in he has died). If he texts back again after this... then this is a hint of interest. Even then it might be because he wants to see if he still has you on lockdown..
tread with caution thereafter..
If he doesn't contact you... he's just not that into you.
Don't chase guys! Whatever people tell you it makes it boring and easy for them. Just show enough interest that they know you are interested. None of this taking charge too early on. Guys you have to chase don't like you enough to make you their girlfriend.
Mine is an unpopular opinion on this site but try it because it is a good way to test if he really likes you.