boyfriend leaving for CO

So my bf just left for Colorado for his uncles wedding; he's the best man. I saw him last night and I surprised him with a little lingere and he seemed to enjoy it Bc we wasn't expecting it. Of course we had sex and I have him a bj Bc I wouldn't be seeing him for a week. He plane just took off, n right before he turned his phone off I told him I would miss him. And all he did was use that person emoji thing. Should I feel worried that he didn't say it back???