What to do!!! Help!!!

I was suppose to get my period on the 3rd I’d this month. Took a pregnancy home test on the 4th and was negative. I went to the Doctor that same day for a blood test and it came back negative. Is day 6th now and no period yet. Ever since I was a little girl I had never had a missed period until now. It could be that it’s late because I am “stressed” as the Doctor said but to be honest I had a pretty chill month w/o stress. I’m so confused.