Positive OPK twice in one cycle!??

I had a positive OPK on cycle days 11-14 then again on CD 18 and 19. 
​I used Clear blue ovulation kit 
​CD 11,12 it was high 
​CD 13,14 it's was PEAK 
​CD 18 & 19 High  
​Tomorrow will be cycle day 20 and I will be testing again
​Has anyone ever had this experience?? That does this mean?!