how old is your wife? everything i have read suggests that if the woman is under 35, there is little need for concern if she conceives in under one year. however, if she is over 35, they recommend she sees the doctor if efforts to conceive are not successful after 6 months.
as far as the af being late, i don't think that in itself is a cause for concern. a lot of women have cycles that fluctuate by a few days. unless her cycles are under 21 days or over 35 days long, they are considered "normal"
was your dw on the bcp for a long time? has she gained a lot of weight since before she went on the pill? apparently the body can be quite sensitive to weight gain.... even a 5% increase in weight can, possibly, throw things off for a while. also drinking alcohol can cut down on a woman's fertility by a lot.
have you read "the fastest way to get pregnant naturally" by dr. christopher williams? it's excellent and very informative. of all the many many many books i've been reading on the subject, it is the best i've found.
i will tell you this from a woman's perspective. we all worry a lot about our fertility. some of us more than others!! (like me
) so it's perfectly normal for her to be scared and nervous. my hubby and i have been ttc for about 4 months and no luck yet. i haven't had a normal af since going off the pill. there are days when i get really really down. the best thing that you can do is to inform yourself more and be supportive of her feelings. but it sounds like you're already doing that so kudos for you! best of luck to you and your dw. and please keep us posted.