Opk clearblue advanced

Just wondering for those who have used the clearblue advanced opk have you ever gotten only flashy smiley faces for a while before getting a solid smiley face? This is only my second cycle using them. The first time I don't think I tested as much and had blank circles the first few times and got a solid smiley around cycle day 19. This cycle I am on day 20 and still getting flashy smiley faces.... just wondering if anyone else had that before? I know everyone is different and each cycle is different too but I am just wondering if it's something to worry about?