Call your doc first and see what she or he think you should do. I'm 34+5 and my tummy been messed up to but no vomit and I've had slight back pain but not unbareable call your doc honey better safe than sorry
Is your stomach getting hard with the cramps? If you are having contractions, your stomach will get hard. Some women vomit when their contractions get bad, but I don't think it's super common. The running stomach is more common for labor. Do you have a fever?