When To Check OPK ?

Fara • www.instagram.com/farangismua
Hey Ladys, Im currently TTC and I check OPK every day in the morning and evening. Every morning I have a faint line and evening the line appears almost like a postive line almost like its getting there, but the next morning the line is faint again.  When do you check for OPK? What is the acurate time? Im currently on cycle day 14 and On my 1 cycle of Clomid. 
Many Thanks