welcome to healthcare magic.
what is your age? you should get your self examined by a gynaecologist. you will need to get a sonography
of the pelvis as well as of the whole abdomen done. also get your thyroid
profile , prolactin
and serum lh anf fsh levels done. if all is ok you will be given a medicine (progesterone
) to bring about withdrawal bleed. do not worry, instead of just wondering what it could be, better you get yourself evaluated.