feeling anxious

doctors office called and said there were antigens in my blood and I need to go to a different place to be monitored to keep track of them. I haven't had that appointment yet, and I don't know what to expect. nurse didn't tell me what kind of antigens, so idk if I should be really worried or not. trying to relax until I talk to the ppl who can tell me more. anyone gone through this and can give advice?