Which is more accurate?

I had a transvaginal ultrasound on the 5th of October and it showed baby was either 6 weeks or 6 weeks and 4 days. I should have been either 7w 5d or 8w 1d and I had an Abdominal ultrasound and it showed baby was only 7w1d. This was an 11 day difference. Seen baby much more clearly with vaginal so wondering how accurate the abdominal one was since we could barely even see the baby it just looked like fluid most the time?