After pregnancy a woman's cervix has typically received some significant damage, which can typically take about twelve weeks in order to heal and allow for a normal cycle to return. Thus, it can take between two and four months in order to return a woman's cycle back to normal after pregnancy has occurred.
You can expect your menstrual cycle to begin anywhere from a few weeks, to over a year if you are breastfeeding your baby. The normal range for this if fairly wide.
Normally the period starts back after the breast feeding is stopped. But since childbirth you are not having any bleeding, there are chances of continuing same process. Consult a Gynaecologist