Just read your 1st post again, was it your normal GP that gave you the nordette? Or a gynae? If a GP, then absolutely DON'T take it!
Did you have problems falling pregnant before? Taking any meds to help you ovulate etc?
As long as you get your period, even if it's a few days late, the assumption is that you ovulated the month before. The general rule of thumb is, take the length of your cycle, subtract 14 days, the remainder gives you more or less the 3-day window where you should be ovulating (under normal circumstances). Take the first day of your period as Day 1.
Have intercourse two days after your period finished, then every 2nd day, up until day 18 of your cycle. You can't miss ovulation then. Sometimes you'll ovulate poor quality eggs and will need some help to improve that, that's where the ovulation scan comes in. This scan is done at your gynae.
I'd just "try" this month and next month, and then see a dr in your 3rd month if nothing has happened.
What annoys me here is that Nordette is quite strong, if the Dr just wanted to regulate then he could've given a light pill like Diane. I can bet you that you won't fall pregnant in month 4 if you take Nordette for 3 months, it'll take your body a while to get rid of the effects of the pill again.