Hi, I'm Dr. Bonk. Pregnancy, labor and delivery can be very nervewracking! There is definitely some variation in that 150 days. Just like people, some goats will have a shorter gestation length and some will be longer. All of the signs you mentioned are normal signs that she is getting ready to deliver. Another one would be if the baby drops down, making her sides look sunken in. As far as the bagging up, some goats, especially first time kidders may not bag up until after she delivers, so that is normal.
Her change in behavior, the not being as lovey, can be a sign that she is getting ready as well. Typically as labor gets closer, does will separate themselves from the group and may become more agitated. She may also increase her activity level.
As long as she is eating well, doesn't seem to be stressed and you can see fetal movement, give her another 2-3 days before you start to worry. If she presents with any of these signs, it would be time to see a vet.
I hope this helps. Please contact me with any further questions you may have. Thank you and good luck!