EDD curiousity

What is more accurate EDD by LMP or EDD by Ultrasound? 1st day ng last mens ko is March 9 2019 which is ang EDD ay Dec 14, sa first Ultrasound ko is January 4 then 2nd Ulteasound ko naging December 30 na EDD ko? Tama lang ba ang bilang? Naguguluhan ako. Sana may makatulong. Irreg ako since then.