Okay so my lepord gecko that I am fostering layed an egg about a week ago, and I think it’s unfortunately going bad. The lepord gecko was given to me so I could socialize and get used to people so she can find a loving home. I have done lots of research in reptiles in general so I thought getting used to different kinds of reptiles would be good for me. We had her for about close to 4 to 5 weeks already, about 8 or so days ago she layed and egg in her cave. I was never expecting an egg and if I thought she was going to lay I would have given her a lay box, she only layed one egg which I think is normal considering this is probably her first egg ever. She was co-habed with some other geckos before we got her, so I think she some how accidently bread with a male. At first the egg was a little dented but white not yellow or slugy in any way. Because I was not prepared for an egg I had no pearlite with me, I only had spagnum moss. I put the egg in a sealed small container with damp moss, it was in there for 2 day and was still looking okay. I bought a small gecko egg incubator on Amazon, again I didn’t have perlite so I put damp/wet moss in the bottom of the incubator along with some peases of reptachip because that’s what I had. It’s been I there for probably 5 days now and in the pased 3 days or so it has been look not so good. It has turned more yellow/window color, I did candel it and I can see red at the bottom of the egg, which looks like an embreo I was a little worried at first because the embreo is usually at the top of the egg I have herd it’s also sometimes happens. The other night I was checking on the egg when I saw little spots that looked like mold or something…I realized it was not mold (looking at it more closely) I read that the hilumitidy was probably to high so I left the lid open for a hour or two, this was at night so I just left the lid half open during night. In the morning I chancked again and it was denied and more yellow. The room that its in the the warmeds room in the house it gets to 87 degrees at the highest if I had to guess. Sometimes even higher because we live in Arizona and it’s gets really hot especially during the day. I checked on the egg this morning and it has not undented yet which Is telling me the embreo could be dead. 
I’ll take pictures in a few hours so people can see what I am saying. I reached a little more and I think the egg was exposed to to much dry air in the night I left the lid half open. If anyone has anything to say please do tell me because I have honestly lost most of my hope…but if there’s anything I could do to possibly help it then I’ll do it!