Honey, I know it's hard, but just relax! As the others have said, it takes some time for your body to adjust after pregnancy, breastfeeding, and the pill. Many say up to a year or more. One friend of mine has had three girls, all about 2 years apart, and hasn't had a period since she conceived the first!
Since it will be difficult to figure out where you are in your cycle, just make love when you feel like it. You are most likely to be in the mood when you are ovulating anyway. You could watch your cm for clues too - check out fertility friend's info on charting and observing your cm if you are interested. (google it)
Wait a couple of months, and if there is still nothing going on, then make an appointment with your doctor to discuss your concerns.
All the best!