Help your girl out

Viviane • TTC for 7 years.. IUI 1❌IUI 2❌IUI 3❌IUI 4❌ IVF journey starting September 2021

Hey girls, I'm new here and I'm learning all the abbreviations like dpo=day pos ovulation

But I think that's the only one I know.. the rest feels like Greek to me. Lol

Also, when you count you dpo.. you count from the 1st day? Middle? Last?