3 peak fertility tests, 4 or 5 days apart

I bought the Clearblue Advanced Digital Ovulation tests, and I've had some strange results. I started testing on CD6, got a negative result, then on CD7 I had a flashing smiley, and on CD8 a solid smiley. I know you are supposed to stop testing, but this seemed early to me, so I began testing again with a couple negative results, then a solid smiley on CD13. This time seemed more reasonable, but as I was unsure with getting two smileys so far apart, I continued testing again, with more negative and then another solid smiley on CD17. I don't understand how I can have that many positives in one cycle and so far apart...which one (if any) were correct? My cycles are fairly regular and typically 24-26 days long. Any insight would be much appreciated, I'm starting to think these tests aren't very reliable at all.