Ovulation Help

Z

I have always been worried that I don't ovulate. Being plus size and I have a cyst on 1 of my ovaries. Recently I purchased the clearblue digital ovulation test. For 4 days now I have gotten no LH surge but the line within the test are getting darker. The leaflet advises these cannot be relied on and to wait for the smiling face. Do these line change when you are close to ovulating?