Thanks for your query.
At 5 weeks 5 days, that is almost at 6 weeks, a fetal pole
( embryonic node ) should be seen, which is not seen in your case.
A small collection in the upper pole means that there is some bleeding within the tissues which support the growing pregnancy
If the bleeding increases, this might damage the pregnancy, and it might not grow normally, leading to abortion by itself or necessity of medical abortion
You have not provided date of last menstrual period, so I cannot say whether the pregnancy corresponds to the ultrasound
You can go for repeat ultrasound after a week to confirm if the growth is normal.
By then, a fetal pole with heartbeat should be seen.