Joe was seen on live television running off the pitch after his side beat Middlesbrough 2-0, sending team-mates and fans into a frenzy.
The 28-year-old knew the birth was imminent but had his phone turned off during the win on Tuesday night.
As soon as the final whistle went Day asked boss Michael Flynn if he could dash off to see his family.
“He said gaffer, thank you so much, can I go please?”
On Wednesday Newport County’s Disabled Supporters’ Association revealed an image of thenewborn twins with the caption:
“Congrats to our Keeper Joe Day and his wife Lizzie, their twin girls were born during our FA Cup replay last night.”
