Guinea pig..... stuff.... I dont know how to explain it.... sorry

Question
QUESTION: Hey it's Hannah. I have 2 guinea pigs which I have had for about a year... almost... well I thought they were both guys but I noticed a couple days ago when I woke up one of my guinea pigs was mounting the other one.... and not on the head.... it was the other end if ya know what i mean... sooo anyways.... i tried sexing them again and i sort of came up with the same answer other than i saw a slight difference on the possible girl.... so... i think that she ...or he.... could be pregnant.... well only if he/she is a she.... wow i fell stupid lol.... i hope u understand.... but ya.... if u could help that would be great but if u can't i can just wait and find out.... thank you!... and sorry for the confuzzleness (that means confusion.... it was like made up in our school lol) well ya sorry :) and thank u again :D

ANSWER: Hello!
I am not sure quite what your asking.
Anyway try this site- http://www.cavyspirit.com/sexing.htm
Beware there is some piggy porn on this site!!! ;)

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QUESTION: Well i wanna know if my guinea pig is a girl (which I'm pretty sure cuz of wat i saw.... and u gave me that site (thank u).... btw lol :) and I wanna know if it is a girl if she would be pregnant...

ANSWER: Hello!
Okay, you cant really tell until the day comes. Guinea pigs are pregnant for 2 - 2 1/2 months so wait it out.

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QUESTION: Thnx..... I'll just wait and see :) I just hope "she" isn't too old and will die.... but the babies would be pretty cute :D and I just got told by my sister that Lenny (my boy guinea) was ummm ya doing that to Oreo (my suspected girl guinea pig) again... sooo ya. How old is too old for a guinea pig to be pregnant and have babies? I'm worried about "her".

Answer
Well the best time to mate is 4-6 months old. Guinea females can become pregnant at 2 weeks though. After one year the hip bones fuse up and are difficult to be moved apart when the birth happens. This presents risks like the babys dying from strangulation or becoming mildly deformed.
I have had one of my female GPs (Runway) live through a birth with 4/5 babys surviving and she is 2 years old. So chin up and lets hope for the best!