Hi!
First of all, it can take up to a year of trying for a healthy couple to conceive.
If you are under 30, I wouldn't worry for at least that long. If over 30, I would probably start running some tests after 6 months or so. If your periods are regular, it will probably happen soon. If they are irregular, you may want to discuss some medication such as Clomid with your doctor.
Good luck!
Dr B
It may take more time, it took me 3months to get pregnant after i had my iud removed.