showing positive 1 week pregnant

okay so i went to the hospital last night, while i was there for completely unrelated problems they diagnosed me of being 1 week pregnant. how is it possible to show 1 week pregnant on a urine test ? why is it showing up as much as it is this early? is it maybe ectopic or maybe 2 of them? i’m super scared because i had a miscarriage last time so i’m over thinking everything