Working a pregnant ferret

[Aussie Whip 4,125]

I've just kept hobs for the last 15 years but recently got two jills. First day of Spring and the younger one came into season and got mated, they usually come on late Spring here. Can't remember working the jills pregnant or up to what stage it is safe? 

[The one 8,485]

If there just mated or early into there pregnancy i still work them if i need all my ferrets but they wouldn't be my first choice and later on i wouldn't work them 

[Bobtheferret 1,248]

In the wild they would still have to hunt when pregnant, would try and avoid it when they are nearing term