Usually a heifer will take a while bagging up. I've had some almost 2 monthas ahead. Also have some that start springing and the next day there is a calf. Just keep an eye on her.
Seems that my heifers always bagged up anywhere from 30-60 days before calving. They always did it well before time and cows seem like only a few days before.
Same here it depends on the heifer for example i have one prenant now due in august and shes got alot of bag and another one due the middle-the end of june and shes hardly got anything