Info on egg development?

Hi guys I have a few questions for you. Well my story all started last night when i noticed my female het pied was not acting right, very slow to react and seemed not able to control her head properly. not when i first saw this i first thought and dreaded an IBD! Any way this was about 11pm last night and was way to late in the day to do much about it. first thing this morning she was very lethargic and hardly moving, I phoed the vet as soon as they opened and got and appontment for 10.30 this morning. When I got there i told the vet as much info as i could , when she last shed ,fed etc. And being I know the problem could be an IBD but from what I had read about it not all her symptoms matched up. Also there is a chance She could be gravid, I have not seen any ovulation but she was building her body mass , gone of food and heat seeking . any how the first thing to do he said was to see if she was indeed gravid, as this would point us in the right direction. he took her in the back to x-ray her and i waited in the waiting room.After about 20 mins or so he came and called me back in, he said that he x-ray showed she was carrying eggs and showd me a pic of the xray and wish id of taken more notice of how many but was a big clutch for her i would say around 10ish(she weighs around 2.5k). the eggs looked to me like they where fully grown on the size of them but , he said they where not ready to come yet as they where to far up and where not calcified. hes dignosation of what was going on with her was that becouse of the eggs, he felt she add a calcium deficiency and the eggs where sucking all the calcium n her body. I have to pick up some calcium gel from him tomorrow morning and give it to her two/three times a day and see how she is in 7 days. but if my dates are right she is due This saturday !!!now my questions arewhen in the development of the egg do they calcify?Think I read somewere it was just before they lay but just want to check on that .and also has anyone else had this sort or issue with females?and how did you get around this?