Someone at work vomited last night but had no symptoms, i was around them today for 4 hours! could i have contracted whatever was wrong with them?

Depends: This depends if they vomited for infectious reasons. If this was due to a viral infection, it's certainly possible you may have contracted their illness. However, if due to a medication side effect or other non-infectious reason then this would not have been a transmissible event. The incubation period for viral GI infections is usually 24h-1wk so you should have an answer soon.

Unlikely: One episode of vomiting does not suggest a contagious illness. Even so, just being around the person without contact would make catching something unlikely

Hand hygiene: As long as you did not clean up the vomit and had not shared food or utensils with that person, you should be fine. Always wash hands carefully, and efficiently...