poofed outta no where 😕

So, I've been in a long distance relationship for 2 years now. And everything always works out for us like fights, etc. but recently this past Saturday. He went to prom with another girl. Which I had no problem with, I wanted him to have fun and have the whole prom experience. He went. The next day, he calls me and we have a long fun convo on how it went. And everything seemed fine. Nothing was wrong. Till the next day after the convo he just completely stopped talking to me. I struggled to get texts back. And now he doesn't answer my phone calls, or texts. It's been almost three days now. I know he's okay. He posts on Facebook. He's just completely ignoring me. I don't know what to do... Or what to think... I need some advice.