If you're coming off the combined pill, it is recommended that you leave at least three months before TTC to get the hormones out the way and to regulate your cycles.

Coming off the OCP I had the following cycles:
5wk, 6wk, 6wk, 6wk, 6wk, 8wk, ?maybe 5wk but pg so I don't know.

It takes your body a while to sort itself out, particularly if you've been on the Pill a while. As you can see, longer cycles weren't a problem for me conceiving; as soon as we decided to "see what happens" I fell pg. We weren't going to actively try for another 7-8 months.