The test can be positive anywhere from about 2-3
days prior to a missed menses to 4-5
days after, but usually it should be done 7-10
days past your missed period.
Otherwise you can get a serum HCG also done which is more specific than urine pregnancy test.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor.