In roughly four weeks, Rob Kardashian and his fiancée Blac Chyna will be welcome their first child together and the anticipation is mounting! Now, while these two are seemingly overjoyed to take on the new challenge, they?re also looking to make some big changes when their baby arrives?. He captioned the photos with a rallying cry to get motivated lose some weight when he becomes a dad: ?Oh yeah we snapping back lol,? he wrote.