Late period

So I have always had very regular periods. This time mine was 5 days late. I felt nauseous and just not myself. I took 2 dollar store pregnancy tests and they both said negative. Then when I did start it was stringy and brown for about a day and a half. Then I past some big blood clots. It lasted about 8 days and then the past couple days I have had brown discharge again. I'm wondering if I had a miscarrige or just a weird period.