Familyman, I, too, did not have an immunization card. I was fortunate enough to pull my record from my medical records from my pediatrician (long since retired, btw 🙁 ). When I did my required physical, my PCP filled out the immunization clearance form, received from my med school.
Foxy, I needed to have documented positive titers for Rubella, Varicella, and HepB, as well as two PPD tests not less than a week apart. If you've gotten health clearance from your undergrad school, you're probably up-to-date on your immunizations, except for HepB (three stage, which you probably have, working in a healthcare setting) and maybe HepA (a relatively new one, my PCP recommended it). Soooo, in other words, you may be able to get away with only a PPD test and a couple of tubes of blood for titers.