Weird sensation in boobs (4 weeks pp)

Spec
I've been exclusively breastfeeding for 4 weeks and still have a weird sensation in my boobs. 
It's hard to describe but the closest I can get is pins and needles. 
Majority of the time it's just uncomfortable but if I get cold (it's Winter here) it's actually rather painful. 
Is this normal? If so, will it hang around for as long as I breastfeed?