What are the signs?

If she really is only 7 weeks old, she will be growing rapidly and gaining weight whether or not she is pregnant. However, I would be skeptical of any age given by a pet store. They probably are just guessing.

You should weigh her everyday and compare to the weight chart
https://www.guinealynx.info/weigh.html
She is still very young and will gain weight. If it exceeds the chart, then you should take her to the vet just to make sure.

The only way to tell for sure is to take her to the vet.

What you described sounds like normal guinea pig behavior.

She's still young. I've raised 2 sets of litters (one was from my own piggy, the other adopted from the day they were born) and even within 2 weeks, you'll notice size change. 7 weeks is very young. They say that a sow must weight at least a pound before she gets pregnant. They don't start sowing until they are around the 6 week mark, so you definetly won't be able to tell anything yet. She's probably just growing.

If you also wanted to know, pregnancy last anywhere from 59-72 days, depending on how big the litter is. The bigger the litter, the shorter the pregnancy. The first litter of a sow is usually quite small, with maybe only 2-3 babies, but it's not unheard of to have up to 8. Babies will be born, fur, open eyes and all and can basically start eating solids after only a few hours. Make sure you start mixing in alfalfa in with their hay and that they get lots of it. Mother can eat it too because she will be nursing. Make sure no boars are present at anytime after the birth! Sows basically go directly into heat right after they give birth and back-breeding is very unhealthy!

Also make sure during the pregnancy, that your sow has plenty of water and fresh veggies. They tend to drink plenty more when pregnant, so make sure their bottle is always filled. You can start them on Alfalfa during the pregnancy, but make sure no other full grown adult(over 6 months) eats or they could develop stones, ect from too much calcium. Hope that helps!

Also make sure babies are properly sexed and separated by 3 weeks, or 21 days. Keep a close eye because some may get frisky before that time period!

Pregnant or paranoied?

OK here is a pig of my piggy, already posted a thread asking signs of pregnancy. Sometimes I go to her and think 'woah, you have got big,' even over night.

I am going to weigh her today. I feel lumps on either side of her tummy. One side is a bit bigger, i think. Not sure if this is how a normal guinea pig's tummy feels.

What do you think? Here is a few pics.

Re: Pregnant or paranoied?

oh, sorry about spelling there!!

Re: Pregnant or paranoied?

Ok, she is roughly 800-825grams and just about 8 weeks old.
Does this sound right, wrong? Way too heavy?

If she IS pregnant, it was at a pet shop. But I will take care of them.

I have merged your threads since you are asking on the same topic about the same pig. Please keep relevent threads together. That way members do not have to hunt down previous threads about the same issue to get the full story.

She does not look pregnant to me. Since she is young, she could be growing due to a better diet. The only way you would know for sure is to take her to the vet for an exam and/or x-ray or ultrasound.