According to the midwife and fertility expert Zita West, you are very fertile after coming off the pill. It's a good time to start trying as soon as you come off it.
She said, often probs with TTC are because people are not baby dancing enough or at the right time as they don't know their cycles. Really interesting stuff.
I took several months before I got pg but we were guilty of the above, not baby dancing at the right time and probably not enough to start with. I then used OV sticks and learnt when I was ovulating, the second month of using them I got a BFP.
Good luck with TTC.