Should the man say "I love you" first? (In a hetero relationship)

I've been going out with my boyfriend almost 6 months now, and he's definitely the best I've ever had, and he feels the same about me. It's definitely a serious, affectionate relationship (We're both in our early twenties). We're really happy together and I knew I loved him weeks ago, but I feel like it's taboo for me to express my feelings first. I'm trying to wait for him to say it first since his last gf hurt him emotionally but I'm having a very hard time keeping these feelings to myself these days!