HELP! please answer clearblue advanced one day peak

Brittany • Proud Mama to Baby Girls Born 8/3/18 and 6/5/20
We just started trying this month. I've been using clearblue advanced. 
Cd13 low/circle 
Cd14 low/circle
Cd15 peak/smiley
Cd16 low/circle 
I'm wondering why I only had one peak day, no high/flashing smiley tests. Normally the past few months I was using the plain clearblue OPK and I typically have a peak smiley on CD18 and have it again on CD19. I've switched my diet, and have been eating healthier. I've been drinking raspberry leaf tea. Today my test said low but the lines were darker than days 13 & 14. I'm planning to still BD today, but I'm concerned it says low. Advise please! I can follow up with a picture of my OPKs.