uro dragon

Question
how long do they carry their eggs? and how do you tell that they are ?

Answer
 The time between mating and layng eggs is approximately 60-70 days depending on how well they were prepared for mating.  Previous to mating they should have properly brumated to achieve sexual potency.  
 A well fed female would be hard to judge if gravid for sure, though expert breeders can tell with gentle palpation.  If the female has well shelled eggs, that could be picked up on x-ray at a good reptile veterinarian.
 In my humble opinion, the absolute best breeder of ornate uromastyx is Lindsay Pike, so any articles or contact with this remarkable breeder would be of interest to you.