If she were mine, I would get her to the vet ASAP. They should be able to tell you if she is pregnant for sure and eliminate the pregnancy. There are WAY to many unknowns for her to continue if she is pregnant, IMO.
Also, you say she is only 3lbs. Again, if she were mine, I would NOT put her life at risk to have puppies...ever. She is too small. She should be spayed and enjoyed as a pet.
Should you decide to breed later, find a dog of standard and a mentor to help you.
