Sarah I think my last chart on ff was the same for post-O rise. It's better I agree to not have to guess.
Herbie, Lottie and I were bemoaning the fact that the digi opk's, brilliant as they are, are very expensive to use and there re no replacement sticks available. Each month would cost £22.99 for a new kit.
I also use a persona and had to check out the website for a contact number and noticed it's the same company who produce both.
Then I noticed the test sticks looked identical.
Once I got the face on the opk and the persona (peak), I used the next days urine to test the persona sticks in the cb digi opk the next day, got a face.
You can buy replacement persona sticks from Boots for £9.99 per pack of 8 tests. Blushingbuyer sells them for £7.85, I think.
If you have a regular cycle and know roughly when you O, then I think you could make on pack of test sticks last 2-3 months.
That's significantly cheaper than any other OPK's, but far more reliable results, because there is no need to interpret the results.
Hope that makes sense.
Welcome back Nappy, glad you enjoyed your trip.