whats the arrow pointing to?

i got this at 6w5d couldnt get a clear pic of baby as i must be much earlier than expected. im worried that the arrow is pointing to something. ive been asked to come back at 9 weeks (5 more days) but i cant help but worry ill be told theres something wrong. baby is sitting just below the arrow so it is not the baby for those saying it is. you can sort of see it