I have PCOS and my cycles are irregular so I chart and usually my charts show a clear shift. This month is a bit of a mess and so I changed fertility friend to the 'research' mode and it came up with the below. So I did a tesco digi with FMU this morning which came up as 'pregnant', but all other tests later on (cb digi and tesco normal) are BFN.
I don't trust the research mode. Just putting it out there for some interpretation. My LP is usually 12 days if that helps!