Confused?

I had my first appointment about three weeks ago. My LMP was Feb 19, 2018, took hcg blood test and measured exactly 6 weeks. But after a week I traveled and had spotting so I went to see another OB. In my knowledge, I am 7 weeks. I did another TVS (transvaginal scan) and measured 6 weeks and 1 day. So I was confused about my EDD. Initially I was told Nov 26, 2018 based on the LMP and blood test. Then again, December 2, 2018 as measured from the TVS. Kinda confused which one to follow. I really wanted to know when as I am always on nurture to monitor my baby’s growth.

What should I follow?