A positive IgG rubella indicates a past infection or a high titre due to immunisation and will remain positive. A positive IgM indicates a recent infection and is more important with regards to outcome of pregnancy. Your test may be positive from the past or due to recent MMR immunisation. Repeat titres at 4-6 weeks and a rise in titres by 4 fold from previous value are significant. Did you ever have fever with rash and joint pains? Don’t worry or misinterpret your reports. Ask your obstetrician to check the reports for you.