Opinions?

I’ve had Mirena IUD for about 8 months. The first few months I still got my periods but they became irregular. Last month I started bleeding around the time I was supposed to get my period but it was extremely light which I know the iud can do. I didn’t know whether to count it as a period or spotting so I took a pregnancy test. It was negative. This month I’m 8 days late and I took a test when I was 2 days late. It would be pretty accurate at this time right? It was negative. My friends keep telling me to test again.