Saying the L word

My boyfriend and I are at the point in our relationship that we are talking seriously about the future. He's never told a girl that he loved her, I've said it once to my first boyfriend. Today I heard him talking saying that he won't use that word lightly, and the way he said that made it seem like he never will. I know I love him, but I'm worried about his response when I say it. Is him not saying it or being open to saying it a red flag?