10 days of brown/pink spotting

Averil

So I'm 6 months PP and I've been spotting for about 10 days almost 2 weeks. It's dark brown to pink then back to dark brown sometimes it literally changes every day since I started. I'm EBF and my daughter eats constantly lol 😆 my husband and I have had sex a handful of times and I just took a test and it was negative so rules out pregnancy. Has anyone else gone through this? 🥲 I have been having super mild cramps.