guinea pig sound

Question
QUESTION: The last two nights our female guinea pig has been making a strange noise almost like an injured cat would meow. When she makes this sound she generally will arch her back briefly and is generally not very active during the time all of this occurs. We are worried and going to take her to a veterinarian as soon as possible but were hoping for any information you could give us in the mean time. Is this a normal sound or is there need for worry? thank you!

ANSWER: Sitting in the corner and arching her back and crying is a sign of a urinary tract infection, it can also be bladder stones which are formed of calcium deposits from over feeding calcium based vegetables.
Or a growth in the bladder.

She must go to the vet for treatment.

---------- FOLLOW-UP ----------

QUESTION: This occured in the evening two nights in a row, only in the evening. And has not occured since. She has been eating and drinking a lot more than usual and generally does not distance herself from the water bottle in the cage. We were wondering if there's the possibility of pregnancy?

Answer
Eating and drinking a lot more are signs of kidney problems and she must see the vet. I would not pick at straws in this case
She can only get pregnant if there is a boar present. Making these sounds is abnormal and i still advise you seek veterinary help