check her to make sure she is not egg bound. Have you felt for eggs or are you jsut going buy what the shop said, did they show you how to check? By taking the male away you could have upset her and this could cause problems with her laying.Personally id put the male back - is there any reason why you took him away from her?
Has she started diggin - you will soon know even if you dont see it coz tank will be a complete mess. But if your worried a trip to the vet or even a phone call might be a good idea - make sure they are qualified to deal with reps as not all vets are.
What have you put in her lay box out of interest.
any more Q's just ask we are here to help if we can
Linny