Is my son allergic to milk?

My son has been on formula since he was born, because he would not feed at all. The first month he could drink regular formula then all of a sudden he started vomiting a lot and it was bad so I figured it was because he was allergic to milk so I switch him to Soy, and he would spit up, but he wouldn't vomit like he did before. Now he is 10 months old and will not drink his formula so I was thinking about switching him out to milk. I tried 2% milk at first since that's all I have and he didn't projectile vomit or anything...so what's the deal? Did he get over his allergy?