Confused

I have an IUD and got 5+ faint but positive pregnancy tests, different brands, different colors but they were positive. I got my urine done at the doctor and it was negative. Got my blood done at the doctor and it was negative. I am not pregnant or I had a chemical pregnancy but with my IUD I do not bleed or have normal periods. If I had a chemical pregnancy would I have to bleed it out? I haven’t bled at all. Not even a wipe. What else could cause so many positive at home tests?