Rubella is a highly contagious viral illness. You most likely caught your case of rubella from some else who also has or had the infection at
your time of contact with them.
The most likely reason you have not heard of it is because immunization programs around the world have made significant progress is reducing the incidents of the illness.
Unfortunately around 25% of children born to mothers who have had
rubella during their first trimester experience either short term or
long term birth defect related problems. The problems can be a low
birth weight or as serious as blindness.
I would stay in contact with you gp/md and seek her/his advice whereever necessary.
Mike