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You would require to get a blood beta HCG levels test to confirm if you are pregnant (since you had a positive ovulation). The urine pregnancy tests can show false negative results (a negative test even though you are pregnant) due to less concentration of the HCG (pregnancy hormone) in urine during early pregnancy.
If the blood test also comes back negative, then further work-up would be necessary to find out what is happening with you , and why you have not had your periods.
Discuss these with your healthcare provider/gynecologist and go ahead with further tests and treatment.
All the best.