I’m new to ovulation testing. I use the clear blue advanced digital monitor. The monitor told me to start testing on day 6 of my cycle. The first two days I did the test and it came back low. Yesterday I got a reading of high. The monitor said it detected a rise in estrogen but no LH surge. I got the same reading today. I’m wondering how to interpret this. Am I in the fertile window that my husband and I should be having s#x or should I wait until the monitor shows an LH surge? How long does the surge go for until peak?