All I know is they swell up quite a bit in a very short time during that first 30 days, and then shed. After they have the babies at around 90 days, they go into shed again. Generally this is how it goes, but I know that they always end up needing to shed at some point during the pregnancy and I know that can happen at any time during the 90 days. Occasionally, they will shed twice during the pregnancy or go into shed and be opaque during the delivery. The rest of the year, it's back to the usual 3-5 months shedding frequency for large adults.