Welcome to HCM.
It is probably due to early implantation
bleeding or abortion
.You have to confirm by doing TVS or USG.
After that you consult with your doctor and take advice according to report statement.
You may do a home pregnancy
test with urine for beta hcg
to detect presence of conception.
If test is negative,then have to rule out for other causes of delayed period.
Take healthy diet and proper rest.
Wish you good health.