Looks like your timing was good! One and two days before are considered the "best" days for conception and some places I've read it's two days before because estrogen peaks then, which makes your CM the most optimal for sperm to swim through, and then the LH peaks the day before to release the egg. Of course, there's a bit of an overlap and it can be a few hours apart for these things to take place or longer than a day. Everything's kind of subjective, so it's more of an average. From what I've always been told, the 72 hours prior to O are the best days due to sperm having an average lifespan between 48-72 hours and it takes an average of 8-12 hours for sperm capacitation, the process that matures the sperm to be able to penetrate an egg (capacitation takes place inside the woman and is triggered by her fluids). In any case, it looks like you've got things well covered, so hopefully a nice BFP will be showing up in another week or two! I got a positive OPK today so I'm not too far behind. Yay! I think I'm looking at another CD25 O day.