8 week old female shitzhu

Question
I just brought my new puppy home on fri.  She is an 8 week old female shitzhu.  She has done great since coming home, has eaten well and drinking her water well.  Only one problem, Friday night she vomited three times a yelloe clear fluid.  I thought it might be all the excitement and the kids playing with her.  She continued to eat and drink well and did not have any problems on Sat.  She woke up this am and vomited again a yellowy fluid.  She has had her first round of shots at 6 weeks and has had pepzide given twice.  What could be the problem.  I am going to try to get her to the vet ASAP.  She is eating puppy chow with water and also soft puppy chow lamb and rice formula.  I did not continue the powdered milk they were giving her at the breeder.  They wanted me to continue for two to three days but I am weary about milk.  Also, she has had BM's that were pretty much black and formed, this am, she had one that was slightly slimey.  Any suggestions?

Answer
Has she been checked for worms? Be sure to take a stool sample in for examination. What is pepzide? Is this something the vet prescribed?

New puppies are always under stress when they change homes, so you should keep her diet the same as what she was on at the breeder's for a couple weeks before doing any changes. However, if it is Purina Puppy Chow that she is on, that is not a very good food. I would recommend one of the Eagle products, Canidae, Wellness, Solid Gold, or Flint River Ranch. Any food changes must be done gradually to avoid upsetting the intestinal tract. Be sure that the kids are not sharing their food with her!

Yes, get her in to the vet. That should always be the first order of business when bringing in a new dog.