I think they might be itchy because of the skin stretching? That's why my tummy and boobs itch, because of the skin expanding.

If it is late O'ing, then at least you know you are ovulating and that's a good sign! You should start writing everything down so you can chart your cycles and then once Septmeber roles around you'll know exactly when the best times to DTD are!

Have a good sleep and good luck testing!