The last 2 months FF has said that i ovulate on day 19 - but this month i took an ovulation perdictor on day 15 and it gave a light positive. Would it be possible for the test to show positive that early? Or is FF wrong?
Is this your first time using OPKs? If so, be aware that there will almost always be two lines. Only when the test line is at least as dark as or darker than the control line is the test considered positive. Some brands require the test line to be darker than the control line, so check the instructions.