How do I breed my Guinea pig?

Question
Hi,
I'm not sure how long I'm supposed to leave my guinea pig (Ebony) with my brothers guinea pig (Roger). I'm also not sure about how I can tell if Ebony is pregnant. They have been together for a day now, at first Roger was very keen on Ebony, but now he just acts like he normally does. Does this mean he has mated with her and knows it? I hope it does!

Answer
Breeding is a bad idea. Here:

http://www.cavyspirit.com/breeding.htm
http://www.guinealynx.info/breeding.html
http://www.guinealynx.info/reproduction.html
http://www.guinealynx.info/handfeeding.html#pups

Where did you get these pigs? Are the related? Do you know their histories? Are you sure they are not roans so you won't end up with lethal whites? Are you sure they don't have poor genetics? You could be breeding lines with heart issues and maloclussion.

Do you have $300 in case of complications and you need an emergency spay? Are you prepared to lose Ebony? There is a 20% chance she will die, or you will lose the pups. Are you prepared to handfeed the babies, if they survive, every hour?

What will you do with 5-8 babies?

On top of that, there are thousands of homeless guinea pigs already and shelters will euthanize them. www.petfinder.com