DIsGirl is spot on. I dont believe Shingles is a contagious form of chicken pox, but its still worth being careful.
I believe in all routine blood screening for newly pregnant mums they test for Varicella, which is the chicken pox virus. So that should give you an indication of your level of immunity.
My XH got a bout of shingles when we were going through a stressful time. It was incredibly painful for him, but I dont remember thinking I was going to catch it. I think he had to take panadiene forte for the pain.
I'm sure it will be OK - but just let your medical provider know next time, or even if you are worried,just give them a call.