Still In shock! Need help with calculating due date please!

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Hi guys so I found out Friday I am pregnant. (Still in shock and does not feel real ). On sat I purchased a clear blue test that indicates how far you are pregnant. 2-3 weeks meaning 4-5 weeks by doctors (I got the off the packaging).

My first day of my last period was 13th November which would mean I am 8 weeks. I just don’t know what to do. Do I contact the doctor, wait. I know you should see your doctor around 8 weeks but I literally went last week because I kept doing pregnancy tests over Christmas all negative so was worried why I my period was not coming. Can you be 6 weeks pregnant and get a negative on a pregnancy test? Baby dust to everyone and thank you guys!