I had mine out in November after having it in for 16 months. I had finally started getting my periods in August, but I was nursing until then, so that probably had more to do with it than anything else.
Anyway, I had mine out around the time of ovulation, but we were going to take that cycle off anyway. I got pg the next cycle, but had a very early loss. I did get pg again after waiting one cycle after the miscarriage and am now 13 weeks 4 days. So as you can see, it didn't take long at all in the grand scheme of things.
Good luck!!
Andi