How long have you been trying to conceive? Were you on hormonal birth control before you decided to have a baby? If so, how long have you been off the birth control? Are you having regular periods?
A couple is not considered infertile until they have been trying unsuccessfully for eighteen months.
It takes a while for hormonal birth control to completely leave a woman's system, so there can be a delay in the return of fertility.
If your periods are irregular, this can indicate an underlying problem that may be to blame for your problems conceiving.