Thanks for writing to HCM
You may be pregnant.
You should repeat UPT after 4-5 days. It may be negative in earlier days due to low HCG
of pelvis is the choice of investigation as it detects pregnancy
Also,Period may be delayed some times even in those ladies who have history of regular periods.
So, you can wait for 4-5 days.
You can also contact your doctor.
Get well soon.