Every couple of weeks my dog will throw up and have soft stool

We have brought my dog to the vet and she got tested for parasites which came back negative. We aren’t sure what it is, she has soft stool for a few days and then will throw up (throw up is infrequent, maybe once every 2 weeks) and then it will go away and she’s fine for a week or 2 before it comes back. She is acting perfectly normal, no lack of energy or any noticeable differences in behavior. I can’t figure out what else this could be, I have noticed her licking her paws could it be something related to that?