I came off the pill about 3 mths before we concieved...
We werent actually trying, we were using condoms when we thought that i was O, i knew nothing about charting cycles and yep, we counted the weeks wrong, actually DH insisted that we were fine to DTD wthout protection that week, and yep we fell pg! Poor DH was so looking forward to months of 'trying'
I strongly blieve that i would have concieved in the first month if we had been trying.

I do however have a friend that it took 3 years for her to, so i guess it depends on you rather than howlong you have been on or off the pill for iykwim

Goodluck