I started taking these ovulation test 2 days before the <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> told me I was ovulating and i got a dark positve (I got the ones tht are specifically 2 lines = positive and 1 line = negative) and then for the last 3 days it was light like if I wasnt ovulating anymore and then todays test is dark again?? Is tht normal