I have gone through your query. Firstly, I would like to mention that Postinor is an emergency contraceptive pill
and is not used to induce an abortion
. This pill contains high hormone content and hence creates hormonal
disruption. Thus there can be menstrual disturbances. Secondly, if you are lactating, the hormonal disturbance can be aggravated and can again lead to irregular cycles. Finally, weight management
is another factor that influences cycles, especially after a delivery. Please get a sonogram of the pelvis, hormone profile and blood counts to plan further management. Hope your query has been clarified.