Hello,Welcome to the HCM,
These symptoms you are having because of
contraceptive pills you are taking now.
As contraceptive pills have hormones (synthetic
progesterone),normaly it works to develope of endometrial tissue and at the end of menstural cycle causes shedding of that endometrial tissue if
pregnancy does not happen so the menses.
Like wise synthetic progesterone causes withdrawal bleeding after stopping the pills.
As you have missed the withdrawal period but if you want to continue
contraception and avoid pregnancy you may continue the pills and stop after 21 days of pills as before. Since you are having side effects (
migraine,stomach ache) if these symptoms bother you much ,you may use condoms or intrauterine contraceptive device instead of taking pills after discussing with Gynaecologist.
Hopefully my answer is helpfull.
Regards,Dr.Maheshwari