How to tell if my rat is pregnant

Question
I got my rat a little over a week ago. When I got her she was very friendly. But lately she doesnt want to be held and has gained a lot of weight. We think she is pregnant but want to know for sure.

Answer
Rats can get pregnant when they are 5 to 6 weeks of age. If your girl was still in a mixed-sex tank at that age then she is most assuredly pregnant.

You probably won't be able to tell for sure if she's pregnant until 3 to 5 days before she gives birth. Mood changes due to hormones, and weight gain are two of the symptoms of pregnancy. She will gain weight around the middle as her babies grow and she will eventually look like she has swallowed a tennis ball. The hair around her nipples will recede, making them look larger and her body gets ready for lactation. She will start a frenzy of nest building closer to her due date. Give her plenty of paper towel.

Here are some links that will help you through her pregnancy:
http://www.worldofrats.com/ROUSBreedingFAQ2.html
http://www.altpet.net/rodents/rats/rf21.html
http://www.altpet.net/rodents/rats/rf22.html
http://www.afrma.org/pregrat.htm
http://hometown.aol.com/RistoRat/nutrition.html

spazrats
http://spazrats.tripod.com