5? I should think that that’s cutting it awfully close–not a problem in a “we’d kind of like to wait another few months for Reason, but it’s not the end of the world if we get pregnant now” situation, but in a life-or-death one…oof.
Sperm can live up to 5 days or so in fertile mucus, an egg lasts 24-48 hours, and if you’re going to ovulate twice, it will be within 48 hours of the first ovulation. Most women have at least 3-4 days of fertile mucus pre-ovulation.
While I haven’t used the LadyComp personally, it’s based on temperature plus an algorithm, not unlike Marquette (hormone testing plus algorithm). In temping methods, isn’t 3 days post-ovulation-temperature-rise considered the bare minimum for determining ovulation–and that assuming no second ovulation? (Which, I grant, is rare, but certainly not unheard-of.)
So…five days pre-ovulation plus another three post-ovulation would have 8 days being a bare, bare minimum for abstinence. Too, bear in mind that if NFP is going to fail, it’s far more likely to fail in Phase I: all it takes is an early ovulation, or some long-living sperm, or a combo of the above. And that’s assuming very, very consistent cycles indeed–like, lengths within a day or two difference max.