Thanks for the query.
Poly cystic ovary disease will cause menstrual irregularity by causing alteration in the hormonal
levels. So your doctor has kept you on hormonal pills to regulate the cycle.
But there pills are having the contraceptive
effect and you cannot get pregnancy
while being on pills.
Once you stop the tablets, the normal menstrual cycle begin and you can get pregnancy at that time.
As you are getting withdrawal bleeding now, that could be light usually.
If there is no residual tumor
and your renal parameters are normal now, that may not have impact on the menstrual cycle.