Allergy to egg yolk

Hi all, my son is 9 months old tomorrow. He threw up twice 2-3hours after he ate egg yolk (mixed with sweet potato and banana, he never had any reactions for either of these). And it was projectile vomiting.

The same happened 3 months back with egg yolk (added with a small bit of olive oil). But this was the same day he got his first flu shot, so we were not sure why and I tried feeding him egg yolk again today.. and the same repeated.

Now it’s confirmed egg yolk doesn’t agree well with him .. I feel very bad that I fed that to him again today, but I was just thinking his digestive system might have matured from 3 months back.

I have 9month well visit with ped tomorrow and I will discuss with her.. but I would like to know if anyone has experienced the same kind of reaction to egg yolk with their little ones.. and by the way, I and my husband are not allergic to anything. Thank you for sharing.