I have three females right now that I think are pregant any ideas to tell that they are/aren't???
If she was supposed to drop eggs, there is a good possibility that you can feel some small (small grape sized) lumps inside of her belly. This is not always possible, but I have quite a few females that I easily can feel.
***Be careful not to push on the eggs, you can cause a rupture inside of her and cause serious health issues and/or death.***
Of course, the only way to be 100% sure is to have and ultrasound performed on her at your local herpetological veterinarian. They should be able to show you the follicles/eggs inside of her if she is in deed gravid.
Though, as Angie stated, if it was around three weeks ago you expected her to drop. Chances are, that she was never in fact gravid. Though, there is a chance that she has become egg bound, due to improper laying conditions being offered to her. Does she dig rambunctiously? Or roam her cage relentlessly?
If she is exhibiting any of those behaviors, place her in a lay bin. There is a nice thread about the lay bin subject in this very forum.
As far as the breeding issue actually goes, sometimes they just aren't in the mood to mate. I have had several issues with getting pre-shed animals to be sexually active. Other times, a previous breeding pair will just refuse to copulate that day. The very next day (or even just a few hours later), they will readily engage each other. I even have a female that is monogamous, i.e. she will only mate to my brutish orange german giant and none of my other males.
Good luck!