Drying-up line or pregnant?

Hey hey

I have an IUD. Last week I felt nauseous after eating everything, and I still had to get a check-up for my IUD & it wasn't visible by the doctor's assistant. Tomorrow I have an ultrasound.

I took a test & it was negative, but later (a day late, maybe silly but whatever) I saw this:

Maybe I can get some clarification. Some say a line is a line. Others say the test isn't accurate etc. Hence my uncertainty haha.

Thanks in advance xx