There are 3 trimesters 1- not too much darker nipples and loss of hair on her tummy 2- she may have morning sickness and gain a little weight 3- her boobies will get ready for the milk and by this point you can really tell she is pregnant she will be just like us miserable. You will be able to feel the puppies by now and maybe even see them moving around in there. Her temp should be 101-102 and 24hrs before she goes into labor it will drop to 97-98? it's fun I have a dog right now that is due in 6 days. You should google pregnant dogs timeline.