Positive Opks on Cycle day 7&8??

Erin • 1st pregnancy-loss at 22 weeks (Patau Syndrome) 2nd pregnancy miscarriage at 6 weeks...trying for our miracle baby
I am so confused...my fertile window was not supposed to start until CD 12 but as I've been testing the past two days they keep coming up positive! I generally have 27-28 day cycles and 2-3 periods...could the tests be wrong?