Hello,
In above condition, you should undergo one
blood test for beta HCG along with USG lower abdomen at the earliest to confirm or exclude intrauterine
pregnancy.
Other reasons for delayed period are
ovarian cyst (most common),
hormonal imbalance, stress/ anxiety, thyroid problem, wt gain/extreme loss, irregular eating habits, psychological factor etc.
You may require some investigations to rule out underlying pathology through USG pelvis, thyroid profile & other hormone assay etc. Consult with your doctor and take suggestive measures.
Avoid stress / anxiety, take healthy diet with
iron supplements, eat more fruits & vegetables and maintain genital hygiene properly.
If you need further consultation with me, then you can visit http://www.healthcaremagic.com/doctors/dr-soumen-patra/63326.
Take care yourself.