My coworker had a stomach virus sunday, mon & tues. today is thursday and i was with her all day long. can i get the virus from her?

Probably not: provided she has been washing her hands.

Possibly: Your co-worker was much more contagious on the days shortly before and while she was symptomatic than she would be a day or two after symptoms subsided. However since we don't know for sure which virus infected her, we can't be sure how long the contagious stage lasts. Keep your resistance strong by using common sense and avoiding fatigue. Some viruses are still in stool up to 2 weeks after illnes

Gastroenteritis: There is a possibility , as sometimes with viruses you can shed virus for a while after you have recovered. But it is usually from close contact and sharing utensils. But as time passes the potential for infectivity decreases. See below http://www.sfcdcp.org/viralgi.html http://www.health.nsw.gov.au/Infectious/factsheets/Pages/viral-gastroenteritis.aspx