Hi fellow ttc'ers. Posted this elsewhere but am new to forums...unsure on where to post, so here goes - Can anyone help with CB digital opk? (The one to detect 4 fertile days). I used it for the first time last month...went straight from low to peak (static smiley) with no high days - instructions said ok....so I used the rest of the sticks this month - was late af last month so confused with cycles so started early cd6 - low fertility as expected. Today cd7 went straight to peak (static smiley). No high fertility again. Cd7!!!! Seems way too early. I usually have 28 day cycles (last month 31) Only just finished af. So I did a boots opk and that says low Lh surge. Which one shall I believe? Could CB digital be wrong? Cd7 seems to early...would make ov day 8 or 9. Can anyone help? Which to trust - boots or CB digital?