Do I need the Hep B vaccine to work an externship?

I always thought I had the hepatitis B vaccine, but wasn't able to find the paperwork, and just put it off for later. At my school I could "opt out" for the clinicals, so thats what I did. I just got an amazing opportunity of an externship for this summer off from school at a hospital in a different state, but now I'm worried about the Hep B thing. I got titers drawn, which came back negative! My mom insists I got the vaccine, but I can't find it at any of the doctors I went to. I'm thinking my mom never got it for me and was just confused. I have the first of the 3 shots scheduled for today, but they won't be done until the very end of the summer, way after the externship is over.

So those who work in hospitals or have knowledge of the situation. Should I be OK? The externship is only 10 weeks. I don't have the paperwork to know yet if I definitively need hep B, but I should get it in a few weeks. What has been your experience with this vaccine? My future kind of rides on the answer
They will let you know if you need it. You may have had the series before but didn't convert. It isn't unusual, especially with Hep B it seems. I would call your new employer and just ask if you need it and explain the situation. Chances are if they do require it andyou have restarted the series they will be fine with it as long as you keep up with the schedule for it.