DPO help please ?

Jackie • wife | mama x 3 | life luvah | 🌈 due 11-1-18
Hi ladies! Im trying to get a grip on this dpo thing, but can't seem to figure it out. I don't temp, but I did get my darkest OPK on Nov 3rd (cd 9). Glow has my fertile window as oct 30th through nov 3rd. Can anyone help with how many dpo I may be?