Hello, thanks for using Health Care Magic.
Lactational amenorrhoe ( absence of menses ) usually is the cause of most absence of menses following delivery. this is due to the sucking reflex which inhibits the release of a hormone called Luteinising hormone that enables developing follicles to produce enough oestrogen needed for their growth ( contrary to previously thought that it was
prolactin). However, this is is possible when there is effective
breastfeeding ( breastfeeding the child on demand and as many times as possible, exclusively on breast milk etc). Return of menses after lactational amenorrhoea varies considerably from individual to individual ranging from as early as two months to as long as three years.
However, it is possible to have other causes such as hypo-functioning of the
pituitary gland ( common in women who bled too much during delivery), ashermann's syndrome (common in women who had D &C, uterine evacuation etc), etc.
What i will advice is for you to avoid stressing up and see a gynecologist at least for support and to rule out any possible cause.
Best regards and hope this helps.