Painful nipples ?

Becca • RN, mama to two daughters, recurrent pregnancy loss survivor, 🌈 baby # 3 on the way
Usually my nipples are a little sore/sensitive right after O--it's how I know I o'd. They're usually fine by 2dpo. 
I'm 6dpo today and they have just been getting more and more painful, they feel bruised or like there something sharp in there, my bra hurts and sleeping in some positions hurt.
Anyone have this during the TWW? Is it normal or an early sign?