Hello Angeline,
Birds are not "pregnant". The egg is developed and laid within a space of days so if there has been a big egg shaped bulge for more than 2 or three days, you should be heading to the emergency vet.
Around laying my hens get a bit swollen but it is not an egg shape so the difference can be visible between swollen (in general large) and with egg (an egg shape).
It is always a good ide to take new birds to the vet when you bring them home for a wellness check so she was due a vet appointment anyway.
You want to be using the calcium under vets orders, too much calcium can create hard shell and make it harder for the egg to pass.
I would ask for pictures but it can be hard to photograph egg bumps or swelling so you are best just heading to the vet to have it looked at in person. Hopefully all goes well
