I know this piece of advice isn't of any use, but everybody will say this: Just keep on trying.

How long have you been trying? I'm sure not that long. It differs per person. And man, I know what you are talking about. I've told a couple of friends in the beginning when I just learnt about it (the same day even) and they got LDs within a week. I never had one (in 8 months&#33. The thing is, if you're too obsessed, it won't work. Let it come naturally, but do try induction techniques.