Boyfriend seems so distant after I said I’m pregnant..

My bf and I have been together for 3 years and live together.. we have been trying for a baby for a while and it just never happened. I found out I was pregnant yesterday and I am so scared but so excited and blessed. He seemed excited and scared. He seems almost mad at me a little. I know people take things differently, I just hope he comes around. I want him to be supportive right now.