Rabbit pregnant?

by Sarah
(Houston Texas U.S)

I have 4 rabbits, 2 females and 2 males. The older female is the younger female and younger males mother but the older male is unrelated. We have decided not to spay the females yet because of the ridiculous costs but the older male is neutered. The younger male is about 5 1/2 months and our vet doesn't neuter until 6 months. He is defiantly mature though and is very interested in his mother and sister :P A few weeks ago (I don't remember exactly how long ago) we let the un-neutered male out to play in our yard without realizing the 2 females were out.

My mom came in to get me to put the females back but they were out about a minute. We didn't think they had mated and basically forgot about the incident until today, when we noticed the older female had dug a tunnel halfway to China and was finding hay and building a nest in this tunnel.

I put the female back in her hutch with a nest box and straw and she's made a nest, complete with fur pulled from her chest. Last time she was pregnant she made the nest the night she was giving birth and I am not sure if this is a false pregnancy or not. She is very cranky and has growled and tried to bite which she usually never does. I really just dismissed the whole thing as a false pregnancy but then noticed small irregular rolling movements in her abdomen. They are not as frequent as her last pregnancy when she had 7 babies but when I felt her stomach I thought I felt something move through her abdomen after a few seconds. She is showing the same signs as her last pregnancy apart from building her nest early and less movement in her stomach.

I was wondering if you think she might be pregnant? And if she is, are we going to have deformed babies? The father would definitely be her son. If someone could get back to me soon that would be great :)