I think everyone is different but I've seen positive tests at 6dpo on here, and they were charting so it seemed an accurate dpo count.
With this pregnancy I got a wicked dizzy spell 2dpo. My DH asked if I was preggo but I told him it was way too early. A few days later another dizzy spell and then again daily for days. It was my first symptom but I didn't test until 11dpo.
I've always charted so I'm pretty sure about my dpos.
PG#1 I was off all week (tired, quit exercising part way through) but didn't test until I was due and my temp didn't drop (14 dpo)
PG#2 didn't notice anything different, tested when I was late (15 dpo)
PG#3 noticed things at 8 dpo that only happen when I'm pregnant (a migraine trigger didn't trigger a migraine and that only happens when I'm pregnant), 10 dpo started getting motion sick in the car (pregnancy only), 12 dpo fatigue. 10 dpo BFN, 12 dpo BFN, 13 dpo BFP
My charts never look different until it gets to the day when my period should start. No matter how many different ways I look at them
At about 4DPO I ate everything in sight, I swear I doubled my usual intake of food and was still hungry. I didn;t test until AF was late and by that point I had no appetite and it didn't really return until nearly 20 weeks.