12dpo...

Hey :) as the title suggests I think I'm about 12dpo :) first cycle using glow and 3rd month ttc off bc pill. My first question is if I'm not temping or cm checking or opking how do I know how many dpo I am roughly. Does it start from peak % day that glow says? I'm confuzzed.... ;p. anyway I gave in and tested morning of 11dpo and got a bfn :( I was expecting it, don't know why but I hate getting my hopes up! Now I'm just going to wait until af.. Did anyone else have extreme af like cramps and feeling yucky at 10dpo? I did then it went away was quite strange... Usually I feel like that the night before af turns up... Fx that this is our month! X