there is no problem with that, your Rh+ comes from your mother
:)
ur father genotype is Rh-Rh-
your mother should be Rh+Rh+ or Rh+Rh-
so you took one Rh- from your father
and one Rh+ from your mother
the result will be Rh+Rh-
and because the +ve propriety is more dominant your blood type
will be +ve even if you have the mix of Rh+Rh-