I'm no expert but she does have that lumpy look of possible pregnancy i think
@Wiebke is clued up on pregnancies, i have tagged her in for you.
would you be able to put your approximate location, country, state or county in for ease of members giving more relevant advice, good veterinary practices to try etc. Go into the tool bar at the top & alter it if you can.
Also have a look in the pregnancy section, as experienced members look on there to help out with any problems that they can help with

OMG! please do not withhold food from her for two days, bloat & pregnancy have two completely different dietary requirements, please get her checked out by a cavy savvy vet, there are some recommended ones on here on the tool bar at the top.
If it was bloat she would sound hollow when gently tapping her middle & feel like a hot water bottle-kind of squishy, but solid all over. Fruit & veg could be withheld for a day or two & reintroduced slowly over time when she improves, feeding her only hay & nugget food.
With pregnancy the babies can probably be felt as ball type shapes & may be felt moving, all according as to how far gone she would be.
do you know how old she is? when was she separated from her siblings or parents?
Also veg can be given & nuggets should be reduced especially in the final stage of pregnancy or it will make the babies grow too large & quickly, which will cause more problems & complications
please dont poke around by her stomach too much yourself though as this could also harm the babies if she is pregnant
She has gorgeous colouring & markings
&

to the forum by the way
