what date do i go off of?

hi guys! so i had unprotected sex on october 28. for context i got carried away and pulled him in and didn’t realize he was finishing. he pulled out like half way thru finishing (if that makes sense). we aren’t trying but we are not really preventing from getting pregnant but i did take a plan b the same day just for extra measure. this happened 2 days before my fertile window is open. i ended up getting a period on Nov. 1st even tho i had just had a period less than two weeks before. my actual period should be Nov. 23 but since i got this extra period the next one would be Dec. 2nd. should i be going based on the Nov. 23rd (regular) or Dec 2nd (probably due to plan b) that way i know when i should test if i need to

posted in another group too