To be sure you're testing at the best time I'd wait till at least 31 days after your last AF. If it's negative and AF still doesn't show then try again a week later.
have you been charting your temps? this is my first month off bcp, and by reading my temp chart (and lots of threads on this forum about it!) i'm pretty sure I haven't ovulated yet.
I starting taking my temp after my 'period' and it has been 18 days. Not sure how long it will take for my cycle to return to normal, i've been on the pill for about 8 years! But im hoping I get some sort of sign of ovulation soon!
you can get a pretty good idea of what happens to your temps around ovulation time by reading the threads on here, or by googling it!