I laughed at my boyfriend when he told me he loved me?

[NaughtyAnna]

I thought he was being funny but it turns out he meant it. We were in bed and had just woke up. It was the first time he ever said it. When I laughed he got up, took a shower, and left for work without saying a word. I called my mum and she basically told me to tell him that he caught me off. I am not sure how to make this right. I love him too but we do not usually talk like that to each other. Is there anyway to salvage this and turn it into a good memory and not the bad one it is at the moment. He will home from work soon.