Stillborn, 4 days early

[Lola56]

Hi, one of my does gave birth to a stillborn today and is 4 days early. Is there any reason for this? This is her second litter, first litter she had 3 healthy kits but this time around she is showing much more and definitely has more than 3, so wondering if it has to do with the litter size? Baby was mostly developed but when I picked up had very sticky skin that sticked to the tissue and I’m unsure if there was bruising on the face or just was still developing veins. Yesterday she did produce a lot of Cecotropes all over the place but I did give her a piece of a carrot and she has been munching on her pellets so I put it down to that and was urinating outside of her litter box which doesn’t happen often, but like I said she is due in 4 days. ( I know they can come earlier but she did have her first litter on the 31st day so I’m expecting she will then too) as she hasn’t started nesting yet. I just want to know if I’m doing anything wrong thanks