Does Delayed Period, Fatigue And Nausea Indicate Sign Of Pregnancy?

Hi , I've been having a few symptoms of pregnancy like fatigue , nausea (without vomit) , I had white clearish discharge once , sharp pain in my pelvic area a few times , took a pregnancy test a few days before my period and it came out negative I was suppose to start my period on the 15th and it is now the 18th and I've missed 3 days already , could I be pregnant ?