I read the Taking Charge of Your Fertility book since my mother had some fertility issues. I went off the pill in February. We were planning to start trying in the July/August time frame, so I figured that was plenty of time to have a couple natural periods and also to get my charting down.
Well, come June and I still didn't get my period, just a little spotting. Towards the end of June (in Disney no less) my chart started to show ovulation for the first time since I went off the pill. I wasn't that concerned since I hadn't had a period yet and we weren't using any other protection. Well, bam, I got pregnant right away. I am pretty certain that was the first time I ovulated since going off the pill. I continued to chart and follow the signs and I knew I was pregnant long before the test confirmed.
We weren't upset or anything, just a little shocked and mentally unprepared that it happened so fast. It took my husband quite a few weeks to believe it. It was also very difficult to get through the doctors heads when the baby was conceived since I didn't have a prior period.
That book is the best! I have let several friends borrow it and they have all gotten pregnant very very quickly (if they follow the technique).