Is my miniature pinscher possible pregnant?

Question
I have a two year old miniature pinscher who mated with my chorkie in the middle of October. We believe she is pregnant but are not sure. Her teats are large and her abdomen has been going back in forth from being really large to being just a little chubby.Her abdomen is tight and feels like a pregnant belly.  We got her a crate just in case and in the last couple of weeks she has become aggressive towards my other two dogs when they come close to the crate. She never before wanted to be so close to me and now she follows me everywhere I go and always wants to be with me. I am just worried that for her since we are not for sure if she is or not. If you could please give me some insight if she might be pregnant.

Answer
If she is pregnant, she should have had the pups already.  You need to take her to the vet ASAP.  If she is that far over due she could have dead pups in her and they need to come out.  You said mid October so she should have had them mid December.   Gestation period is 63 days and it seems she is way over that so you have to take her in and see what is wrong.
nancy