Am i pregnant?

I haven't had my menstrual cycle since the first week of August. I have been sexually active with no protection and have been experiencing unusual symptoms. I've been nauseous in the mornings sometimes, recently started having breast pain and liquid stuff coming out of muly nipples! I've also experience spotting, tiredness and high sense of smell. I went to the doctor I have taken a test and it says negative...I'm concern tho about the symptoms I've been having. Any comments?