You never stated whether or not you actually DO love her. But I'll assume you do, in which case it might be wisest to wait until she tells you she loves you before you tell her. It's something that should be used sparingly, as another poster suggests, otherwise it loses its worth. You can say it once, and mean it, and convince her you meant it, and then not say it again for a while, by which time she may be wondering why you haven't said it lately. Then when you say it again, it will have reassuring value to her. Just as long as no woman gets to think of you as hers unconditionally at any time, I think that's the thing to be borne in mind. Some DJs might call this "being a challenge".