You should not expect pregnancy to happen immediately and you're only setting yourself up for disappointment if you do. Oftentimes cycles are very, very screwed up after coming off of birth control and sometimes it even takes up to a year for cycles to go back to normal and for the woman to ovulate again. It took my body 6 months to go back to normal! I would strongly recommend tracking your wife's bbt (basal body temperature) to see if she is ovulating and when.
Here's the update on our status.....we've been testing with HPT since Thursday (2/19) (all negative) in hopes that my wife ovulated around 2/7 - 2/9 after going off BC. She experienced some early symptoms beginning on 2/15 and 2/16 and lasting on and off all last week. This morning she had light spotting (reddish first thing this morning, brownish second time, then nothing more). Cramping and dizzyness a lot more the last few days. Obviously we know going off BC can mess the cycles up for a little while, but now we're thinking she POSSIBLY could have ovulated a little later (around 2/12 or so). Have also been taking OPKs since 2/16 but all negative. She actually has an appt with OBGYN today (standing appointment) where hopefully we'll get a little more clarity......but my guess is typical answers of wait and see when you get your period.....I'm thinking that IF it was implantation bleeding today, then we shouldn't expect a positive HPT (the higher sensitivity ones) to show it until Wed or Thurs --- right? Keep us in your prayers too please.
It sometimes can take a month for the cycle to regulate itself. Her period will come soon since the hormone from the pill has been stopped. Give it some more time.
You should wait to try and conceive until after her first full period after stopping the pill, which should be in a few days-weeks.
Good Luck!