2nd peak OPK 3 days apart

A
Hi all,
I'm using the clearblue digital ovulation kit with dual hormone indication and I'm a bit confused.
I got my peak 3 days ago and I tested again this morning, expecting to see a low and got another peak result. I started testing on CD7 as I have a short cycle. I test at the same time every day and always with FMU as it says to do. 
This is what my results have been this cycle so far;
CD7 low
CD8 low
CD9 high
CD10 high
CD11 peak
CD12 didn't test
CD13 didn't test
CD14 peak 
Has anyone else had this? Is this normal? I've no idea what to make of it.