Using Opk test strips for the first time during my last cycle was an interesting experience. I started testing at CD 12 and didn't get a positive strip until CD 21 and during that whole time, it was stressful trying to figure out if the test line was as dark or darker. So this time around, I bought Clearblue digital ovulation tests in addition to using the opk strips. According to Glow, yesterday was the first day of my fertile window (CD 15) while the Ovia app showed I would start on (CD 18). Therefore, I started testing yesterday and had an opk test strip that looked almost positive and the CB showing an empty circle. So I think to myself, "Okay, I'm getting there and my CM is watery so maybe it's soon." So hubby and I end up BD'ing late last night (or early morning since it was at 1:30 am) just in case. I tested this afternoon at CD 16 and low and behold, a darker test line that showed up fairly quickly. Tested with CB and bam, a smiley face. So I guess it's a good thing we BD'd last night just in case! Time for more BD tonight and tomorrow. I was just surprised that I got a positive after testing for 2 days compared to testing so much last month. Glad we didn't miss the O, and I just hope I have a good chance since this totally shifted my fertile days on both apps and hadn't BD'd since last month due to my son being sick. Here's hoping the swimmers have a fighting chance!