We've been TTC for over 2 years now and my dr recently recommend using two opks at different times of the day to really pinpoint the ovulation window. Yesterday morning and this morning I got a positive on the first response one with the two lines. However both yesterday evening and tonight I got negatives on the digital version by first response. I've been using the digital one for months and have always received a positive on the day 17 of my cycle. Just wondering if anyone else has had the same thing happen?