my last period was sept 10, on the 1st of Oct i have spotting until the 3th...i went to the dr and…

my last period was sept 10, on the 1st of Oct i have spotting until the 3th...i went to the dr and did a urine pregnacy test which came back negative.....every since the 4th I've been having nausea and head aches.....ive also been very sleepy too along with going to the bathroom a lot more.....this app says af was supposed to start today but nothing has happened just yet.....could i still be pregnant even though the drs urine test said negativemy last period was sept 10, on the 1st of Oct i have spotting until the 3th...i went to the dr and did a urine pregnacy test which came back negative.....every since the 4th I've been having nausea and head aches.....ive also been very sleepy too along with going to the bathroom a lot more.....this app says af was supposed to start today but nothing has happened just yet.....could i still be pregnant even though the drs urine test said negative....should i wait and test again....what else could it be??