In normal circumstances, a pregnancy test result is valid if the test is taken not earlier than 5 days before the next period arrives. False positive results are possible when using home pregnancy tests (urine) in cases of increased levels of Luteinisating hormone (LH). For those experiencing PCOS, LH levels are already increased and menstrual cycles/periods are irregular so you may need to take a more specific pregnancy test. In your case, the best solution seems to be to wait until you miss the expected period and then take a blood pregnancy test (beta); it is a more specific pregnancy test. You can go to your doctor to request such a test.