Hello Susannahferrie , greetings from healthcaremagic.com . I have gone through your case scenario and I do believe urine HCG test or pregnancy confirmation kit are reliable if pregnancy is inside the uterus. Are you experiencing any lower abdominal pain lately on either sides of your abdomen . It might turn out to be a just another aberrant spotting but please do get a transabdominal sonogram to see the uterus, ovaries and rest of the pelvic architecture. You mentioned you have been diagnosed with PCOS , it rarely produces spotting mostly produces irregularity in periods. It is always better to consult with your gynecologist and discuss in detail about further queries. Take care