14 month old vomiting randomly

My 14 month old son just started daycare 3 days ago. The second day after he was there (yesterday) he randomly threw up twice. Once in the middle of having a bottle, and once at 10:30pm. He woke up and vomited ALL over his bed ☹️ but he was acting totally fine right before and right after getting cleaned up! He has the same amount of wet diapers, no diarrhea, and no fever. Today so far since getting home, he’s vomited once. I gave him a bath and now he’s asleep.

I’m just wondering what could cause this if he has absolutely no other symptoms and he still has the same personality? I feel starting daycare just exposed him to all kinds of germs and got him sick but it’s just weird that it’s only vomiting.