you probably need a repeat ANA by immunofluorescence .
that will give us a definite answer about your SLE.
ANA weakly positive means that it has been done by elisa
which is not the recommended method to do the test.
what other symptoms do you have.
do you have photosensitivity
, oral ulcers,
ever had pleural effusion
, CNS or renal symptoms-these are the symptoms of SLE.