U have to do another tests and go to a doctor,,,not to be sure of pregnancy this not the 1st issue to care for, but to c ur menstruation at 1st sign of abnormality u need to have a check always to be sure of ur own health,,,
by the way if u like to ensure of the result of the pregnancy best at the 1st month to have a hormonal blood test,,(if those 3 tests of urine sample),,,