My guinea pig behavior

Question
I have a guinea pig i got in Jan of 2007, did not know she was pregnant, she had 3 babies 3 weeks before easter, one was a male, and i realize the male was tring to get on top of her, so that day a friend of mine wanted the male so i took the male pig which was one of her babies, to my friend, well i notice now she is likes to lay on her side alot, and i'm worried she could be pregnant again is there anyway of knowing the early stages of pregnancy?  

Answer
Lucy,

Here are some signs that help in telling the early stages of pregnancy.

Drinking lots of water,
Eating more,
Becoming noticeably heavier,
Teats become more prominent and red looking,
By the round belly she'll get further along.

If she is showing two or more of the above signs then she is pregnant again, but if she isn't then keep an eye on her for a week and see if she does show the signs or not, if not then she is most likely depressed at being separated from her son as the form strong attachments to each other.

I hope this helps,
  Take care,
     Jules