Claiming child

My first year filing taxes as divorced. My ex husband is allowed to claim our son as a dependent this year. However, our son did not live with his father more than 2 months this year and I was told I could claim the EIC and head of household. Now my ex is saying he can’t claim our as a dependent which he should be able to. Am I in the wrong for claiming the EIC and head of household or can he still claim him as a dependent?