Hi thanks for your question.
Your having painful periods and want to take birth control pills for that.There are many causes for painful periods and uterune fibroids and endometrosis are the commonest one.Your gynaecologist can tell you cause of your painfull periods after examining you.There is no need to rupture your hymen
for examining you.There are many investigations like ultrasound
which can pick up most of causes of painful periods.Your gynaecologist may prescribe you medicine for treament of pain as well as for postponoing of periods.Being Hepatitis B
positive will not interfer your treatment,however you have to remain under supervision of your gynaecologist who may monitor your liver
function regullary till you on medication for postponing periods.
Hope this answers your question.