Corid is not going to help if she's having reproductive issues. It won't hurt her, but it's a Coccidiostat used to treat Coccidiosis (overload of Coccidia in the intestines).
You know that she is in lay right? She's young.
She has not pooped in 24hrs or so - not at all? If not, then if she's not in crisis now, she will be very soon. She may be struggling passing an egg, I would not push any further if it's painful for her. Get fluids into her and give her 1 Caltrate daily.
IF She's not lethargic, then you can give her a soak in a warm epsom salts bath. If she's lethargic, you can place her in a steamed up bathroom or provide her with a heating pad to sit on, but make sure she's got room to move off the pad if she wants.