He just dropped off the face of the earth...

I'm extremely heart broken, he met my family while on a week long vacation with them. Said he was sort happy he came and was having a great time. He left 2 days before I did(he is not a trip taker, even with just myself and I was shocked he lasted 5 out of 7 days). When I got home, I called him, no answer, texts, no answers, nothing, its been a week... what the hell happened?!?! 9 years of friendship, 6 months of dating, a baby on the way... and now nothing. I am completely floored and my heart is broken. Why would he do this?