Second period after miscarriage-weird

Hoping someone on here had maybe had something similar and can shed some light maybe.

I had a miscarriage August 5th first period arrived spot on my second was due on Saturday just past. Since Saturday I’ve had no real period though just light spotting on and off (spotting is a mix of pink and brown, changes each time I go to loo) I’m still spotting today as well.

I’ve taken a test last night but it was negative so I’m really confused with what’s going on. Had anyone else had this? Is it normal after miscarriage? Should I test again? Hope someone can shed some light 🙂