Teething?

I think my 12 week old might be teething. She normally poops every other day. But the last few days she has started to poop two or three times a day and today she has pooped 8 times! She also spit up almost her whole bottle which she never does. I called my mom because I was scared there was something wrong with her and my mom thinks that she is teething. She has been drooling but has been in a great mood all day. What do you think? Is she teething? Is she sick?