How can i find out what immunizations i've had if mom forgot?

Several ways: At 32, its tough. Check w/ your previous pediatrician, your college, military service records, previous job (if you were in health care). However, you are old enough that records may already be destroyed. Foolproof way is to have your blood tested for the antibodies of previous shots. If they are present, you may not need more shots, just a record of the immunity, which you should keep permanently.

Several sources: Your doctor should have the records.Also your school, high school should have them. In addition some states have a population wide immunization data base.

Titers: In addition to below, you can also get titers drawn (blood test) that will show if u have immunity to the infections that the vaccinations would protect against. This would tell u whether you've had the illness before (and most likely immunized now) or the actual vaccination in the past. It's also good because it can tell you if you still have protection against the disease or need a booster.