you didn't mention
what was your gestational age
at the time of miscarriage?
what was the reason for your miscarriage?
whether genetic mapping of the fetus was done or not?
Some causes will be repetitive, so if the cause is known better advice can be given.
Anyhow after having one miscarriage and undergoing D&C you have to wait at least for 3 months. In this period the endometrial cycle will become regular and you can regain your hemoglobin