I don't really remember, my last "love" relationships we probably said it to each other a couple months after dating? It was a long time ago....but we had known each other for quite sometime prior to that.
The last time a girl said it to me was a couple months ago, and we had only been dating (as in seeing each other, we weren't bf/gf) for a couple weeks...I kicked her to the curb a couple days later. She was a great ****** but dumb as a rock.
I probably won't say it for years to come...I've had some ****** up ****** happen to me in the past 5-6 years where it's real hard for me to get emotionally attached to people...which, in reality, is probably a good thing.