I didnt have this issue as I had my shot 10 years ago and my immunity is still ok.
Its a bit tricky to stay away from people who are contagious because I think the measles/rubella rash appears after the time that it is contagious... i dont even know what mumps is though.

If it was me, I think I would just try to be careful around people who might be more suseptible to those diseases like children, and stay away from people who have been near people who have recently had measles because they could be contagious with it..