My year old pug has been vomiting?

Just the other night my pug woke up twice and vomited up dog food. She vomited twice more that day all food she had eaten that day. She acts normal playing and drinking water. The only thing i have done different is I started giving her greenies and I was giving her one a day, however i have heard they are very potent and maybe that is cause for her vomiting up her food. Help!