“Probable” SCH?!

Zoe

Had an early ultrasound done due to some lower back pain (ended up being unrelated) but the paperwork says “probable subchorionic hematoma”

Why would it be probable and not a for certain thing, could it be too early and it’s a second sac with no yolk sac or something?

They saw a yolk sac but no fetal pole so it’s still very very early (5w4d measuring 5w2d)