I've never been allergic to peanuts and i eat peanut butter all the time ... now nervous about being allgeric. can it be possible?

No allergy: If you eat peanut butter and have no reactions then you do not have an allergy to peanuts.

Highly unlikely: The ultimate test for diagnosing food allergy is a food challenge, which you have successfully performed. Even if you have a positive skin test or rast (a blood test), you are not allergic to a food if you can ingest it without any reaction.

Not allergic: If you are eating peanut butter, then you aren't allergic to peanuts.