Its a bit of a grey are when you come off any contraceptive tbh.
I came off the pill 9 months before starting to try for my son and my cycles ranged from 21-30 days, so a bit all over the place.
Some people are lucky and fall straight away, others take while, just enjoy the practice in the meantime ;)
Most Drs or Midwives would suggest waiting until you have had a period before you start to try but this is really more for the reason that it is then easier to date your pregnancy.
And remember your folic acid ;)
Good luck!
SB x x x