Stats on falling pregnant with a cut-off?

Does anyone know what the stats would be for falling pregnant with a cut-off? I'm guessing the bigger the cut-off the less likely the chances of falling pregnant. Reason I'm asking is that I recently bought a fertility monitor with the idea being that I try and figure out my cycle before trying to conceive next year April/May. It looks as though I accidently have a 3 day cut-off. I was expecting to O much later than what the monitor confirmed . Anyway I'm just wondering what my chances are statistically. If I do fall pregnant now it wouldn't be the end of the world although ideally I would like to do a much better sway.

It really depends on your natural PH and the quality of your cervical fluid, in good CF and an alkaline environment sperm can live for at least five days. You still have a good chance with a three day cut off, what was your CF like?

Unfortunately I've never been very good at reading my CF. I've never had stetchy ewcm. Only on very rare occasions have I noticed white CF. For the most part and the whole way through this cycle it's been skant. This is one of the reasons why I bought the fertitlity monitor as I really struggle to read the signs and symptoms leading up to O.