It is. Somebody has to say it first, why not let it be you? While I understand the hesitation and the prevailing notion that a woman should always let the man say it first (since most men are the holdouts), the fact is, not saying it can be just as frustrating and grating as saying it and receiving a "thank you" back.
Here's the catch: you should only say it if you and he are both in a place that you think is a "love thing". Like, you shouldn't say "i love you" after the second date. Mostly because that's ludicrous.
Love is an odd monster. It requires people to jump out of their comfort zones and do and say things they'd never say. It's a good feeling and if you have somebody experiencing it with you, taking that big leap shouldn't be so painful. Of course, you have to be ready to fail (him saying he's not there yet), but love is an honest emotion. So I say let her rip and share your heart and feelings, unless, of course, the situation is completely insane like some prison pen pal you met two weeks ago who wrote you the greatest poem ever and you can't help but be in love now.
But then again, who am I to question love. And just remember, SOMEBODY's got to say it first.
Maybe this is a story of what not to do...idk. I had been seeing this guy for only a week (although we had 5 dates in that first week). We were sitting on the couch making-out when my mouth just blurted out, "I love you." There was no forethought, it just came tumbling out. His eyes got big and he replied that he always thought the guy would say it first, but was pleasantly surprised that I had said it. He didn't reciprocate that night, but it really wasn't awkward either. He told me he wanted to say it, but wanted to make sure he was feeling it. Two days later he told me he loved me, two weeks later he proposed and last month we celebrated our 22nd anniversary.
So, heck yeah, tell him if you want to (and if you are truly feeling it) - you never know what might happen.
The story of how my boyfriend and I got together:
I was sitting on the couch telling my best friend, the one I've known for a few years, that I was planning on moving. He asked me not to go, and I asked why not. He said he couldn't tell me why. Again, I asked why not. He answered the same, so I told him he could easily find another person like me to hang out with. He said that even if he did, it wouldn't be the same. I asked him if he liked me, and after a moments hesitation, he said yes. I was very happy to hear this, so he asked why I was so happy, and before I could even think about what I was saying, I told him I loved him. He simply said "good deal," with a smile on his face. About a month later, he told me he loved me. It's been about three months since he said those magic words, and he talks as if he plans to have me around in his future.
So go for it if that's what you want to do. Just be sure it's true :)