Thanks for query.
It seems that you might be having some hormonal
imbalance causing this problem.
This may be due to PCOD
(Poly Cystic Ovary Diseas ).
Go for thyroid
test as hypothroid again cause this problem.
Consult gynaec and get all investigations done.
Go for pregnancy
test 7-8 days passed after your expected period date for confirmation.
Ok and bye.