u had laparotomy
and ovaian cyst
has ose been removed.
decision of your gynecologist is good she started BC pill .
u did not mention the name of drug .
some time low dose containing hormone pill cause inter menstrual bleeding
or just spotting .
no need to worry .
wate for some days and even for 2 cycle .
if same problem persist even after consult your doctor to shift on another high dose pill .
start Iron -Folic
hope this will help u .
r nehagud luck