When do you start to count DPO?

Jaye

Soo ladies. I got a bit confused with when I should start to count my DPO. Is it the day after I got my peak on opk? Or is it 2 days after peak? Much appreciate ur replies🥰🥰. Reason I’m asking is according to my app I have 5days til af. I did a preg test this morning using first response. I can see an extremely vvvfl. Not sure if indent. Normally I get absolutely nothing on these tests. It’s like a flat liner (dead) Hahahha. Just curious

Thnx ladies. Be kind to me 🙏🏻💖