After Jack helped Jill out of her clothing they waited as she finished changing into a copy of Jack's original male body.
As Jill was finishing her change Jack got a bad cramp and could not help but bend over from the pain.
Jill moved over to the girl that she now fully believed was her brother "What's the matter, are you OK" he said.
Jack said "I just got one hell of a pain in my gut."
Jill got a strange look on his face as she looked between Jack's legs to see a red patch "OH I think you just got a visit from aunt flow" he said as she pointed to her crotch.
"SHIT" Jack said as she ran to the bathroom.
Jill went to Jack's room and found his wallet then went to the bathroom "Stay here and take care of yourself I will go out and get you somethings your going to need.
Jack wanted to stop Jill but got hit by another pain so she was unable to stop him before he had gotten out of the apt.
Jill left the building as he headed to go shopping to get Jack some tampons and some more clothing.