I don't think you can put a time or a limit to love. People feel differently for themselves and towards their partners. You must realize this. I know that I've always started to say I love you from the second week, and my relationships were all fantastic and healthy, the fact that we broke up had nothing to do with saying I love you too early, but because we knew how much we loved each other that it hurt so much.

So I'd say you can begin to say I love you whenever you can't hold it back anymore, when you feel it honestly crawling out of you.