ClearBlue Digital Advanced OPK

This is my first month using the clear blue digital advanced 0PK. I have now gotten four days in a row of the blinking :-). The directions seem like I would only get two of those in a row before hitting my peak.  Has anyone else experienced this? Also my cycle is very irregular. It ranges anywhere from 30  days to 56 days. I have ovulated on days 19, 24, 28, and 34. So I'm testing starting on my 12th day. It is now day 20. Any help would be appreciated.