Are Guinea Pig Has Swelling In The Face Has Not Been Eating As Much Or Drinking As Much And Not Running As Much Is She Pregant?

Swelling in the face doesnt usually indicate pregnancy.
Guinea-pigs are quite prone to respiratory infections tho, and this can and will make the face and nose appear puffy.  The fact she's not eating or drinking much is enough to warrant a trip to the vets.  Very likely a respiratory thing (a cold or allergy) in which case it can be treated easily with antibiotics and she'll fell much more like eating and being her old self within a couple of days.  Like us when we have a flu or cold, the last thing we feel like doing is eating and/or drinking - especially  with a stuffy nose and sore throat.
(We had a guinea-pig who would regularly get a respiratory infection with cold like symptoms - more likely brought on by  change of hay than the weather as she was kept indoors in her old age.  Quickly fixed each time tho, with antibiotics ~ the vet even allowed me to just phone and request the medicine without consult after a few times)
All the best....

If her face is actually swollen and she isn't as active or eating or drinking very much she may be ill due to an infection or something and need to see her veterinarian. You should have her checked out just in case particularly as you seem to be so worried. Has she been around any others of the opposite sex for the last couple of months? If not, she isn't pregnant. If she is pregnant deadly complications are pretty common so you should have a vet lined up in that case as well.
www.cavyspirit.com
www.guinealynx.info

Sounds like 2 me labour :/ lol..But I think she is pregnant :) congratulation, and good luck if she is (:.....