Hi, I'm A 25 Year Old Male. I Have A

Hi, I'm a 25 year old male. I have a moderna covid shot scheduled for April 3rd. I read that people with an allergy to PEG should not take mRNA vaccine shot, but how do I know if I'm allergic to PEG in the first place. I did some research and I found PEG is in my moisturizer which I've been using regularly without any issues and my shaving cream. Does that mean I'm not allergic ? I'm confused because unlike my moisturizer, the vaccine enters my blood stream