Can Constant Sneezing With Thick Mucus Nasal Discharge Suggest Cat Dander?

Cat Dander . I have the symptoms . I have lived with 2 completely house cats and as of 6 months ago I started having to sneeze several times , with blowing the nose of nasty clear ( sometimes thick ) mucus . I have not been diagnosed by my MD as Dander. He says it would involve several test to determine what is causing the nasal build up or causing the sneezing ( sometimes 6 continuously . I need HELP.