She probably wasn’t pregnant yet having just gotten married.
Rumpel was just coming by to let her know his terms for payment since he had successfully completed his end of the bargain (ie change her life, which was marrying Prince Thomas).
I agree. When Cinderella asked Rumpel what he wanted, Rumpel even said he wanted “something you don’t yet posess but something I know is coming. Your firstborn.” Cinderella then intended to run when she found out she was pregnant until she was persuaded otherwise.