I took one of these yesterday evening and it looked pretty positive for ovulation, but when I took another this morning (actually I took 2 this morning just to be safe) they were both very clearly negative. Did I ovulate last night or something? I'm on CD19 now and I've had 12 days of a 'High' result from the Clearblue Advanced Digital Ovulation Tests, but never a 'Peak' result. What's going on? Did I just ovulate pretty fast last night???