Throwing up after first formula

Hi all,

My 3 week baby had a formula bottle last night, only 2oz. He’s been exclusively breastfed until then. This morning he projectile vomited and then he had another 4 feeds lasting between 6-8 minutes in the afternoon. He then projectile vomited 3/4 times.

Could this be because of the formula? Over feeding? Or both?

He has no temperature, very alert and still requesting food.