My wife just tested negative for syphilis but reactive she is 11 weeks pregnant and both of us have been faithful and neither ofof us have had any symptoms is this a false positive?

Maybe,maybe not: The initial screening tests they do for syphilis and many other issues are lower cost tools (few bucks)to find the subgroup of large populations (pregnant ladies) that need the more expensive (lots of bucks) confirmatory test . There are many things that can cause a false positive.The next step would be the confirmatory test that should give you the answer.

Yes - false positive: False positive RPR is not rare in young pregnant women. It does not mean syphilis infection, rather a predisposition to autoimmune diseases such as lupus. Discuss with your doctor further testing to prove or disprove this theory.