Most Helpful Guy
There is no hard set rule to this, and he might just be busy with other things. You can always text him and see if he responds or continues radio silence.
More importantly, you shouldn't over analyse this and stress yourself out. Play it cool and just see where things lead if he doesn't reply then you are free to find someone better. :)
Most Helpful Girl
My best friend had the same problem. She slept with a guy she really liked, and now he hasn't talked to her in two weeks even though she had texted him first. If you like him then I suggest texting him but it's not the best choice to do so. And if it was a one night stand, then forget about him. But honestly if he hasn't texted you, forget about him. You're so much worth it than waiting for a guy who doesn't make an effort. it's okay to feel insecure but not over a guy! Someday a guy will come and adore you to the fullest, maybe not now but sometime soon.