Hello dear Understand your concern. Some time pregnacy test man kind in your case give negative result if you did early. It give positive result 7-10 days after missed period. It is 95 % accurate. So you can repeat after 7 days if period will not come. Or you can go for blood HCG leveel or USg , that are very specific and accurate. Other cause of delayed period 1. Pregnancy: I think most common in your case, because you have unprotected intercourse. 2. High level of stress 3. Change in life style 4. Late ovulation 5. Excessive exercise 6. Drugs: Birth control pills, tyroid medication, Excessive tea and caffeine 7. Thyroid problem 8. Hormonal imbalance 9. Endometriosis 10. Dysfunctional uterine bleeding 11. PCOS 12. Fibroid/Adenomyosis If period will not come Consult the gynecologist Test your hormone profile, endometrial biopsy, PAP smear. hysteroscopy. Take regular exercise like yoga and running. Eat fruits like papaya, orange and pomegranate. Avoid excessive stress, alcohol and tea. Take proper rest. Hope this may help yuo. Best regards Dr. Sagar