The urine test turn out to be negatif twice, and now period is late at least 8-9 days, is it PG ?

1st test is 2weeks after the than the latest one is 3days ago, both show negatif.. can a urine test tell you wrong result, if the 1st one show negatif i can understand but than the second test also show negatif. using diffrent urine tester from 2 diffrent pharmacy.still negatif, but period already late 8-9 days.. can this be PG??