With the Ovia app it numbers each day of the month with a 1-10 rating on how fertile you are (based on what you have input previously).
It has 6 days highlighted in green which is predicts to be your most fertile or most recommended to DTD according to when it thinks you'll ovulate. Today I am 9.5 (yesterday I was 10).
It does change when you enter data eg. If I had a peak reading on my OPK 2 days ago it would shift those 6 green days to earlier etc...
I still have a flashing smiley today - past two months i've tested twice on "Green day 5" and got my solid around 4pm so "Should" get that today.
Then from there I just need to work out when exactly I ovulate ... EASY haha
I asked my nurse what the harm was in DTD right before ovulation with the idea in mind of "good eggs" and our super sperm theory. She said she had always thought the same way, but I guess the way I have understood it is that it takes so long for the sperm to travel to the egg that it's more likely that that older sperm will due before reaching the egg. Which makes some sense...so perhaps the two best days to DTD are the day right after getting a positive OPK and the day right after that. Which doesn't mean the other days are bad, just that it's longer from the time of ovulation which might mean the sperm is more likely to die.
Just ate my breakfast of pineapple...now I just need to buy more lol...