random spotting after extremely sad situation

I’ve had my Mirena IUD since January 2025 and aside from the first week or so, didn’t have any spotting for over a year. Well the last few months, I’ve periodically had spotting. It kinda varies in color but is most often a dark brown and occasionally a lighter pink/red. I was initially worried I was pregnant because I thought it was implantation bleeding, but dozens of pregnancy tests have said that’s not the case. It all typically occurs when I’m super stressed out but I wasn’t sure if it could even be that. I had a diagnostic laparoscopic surgery a little over a month ago that ruled out endometriosis and other issues. This last week has genuinely be the worst week of my life and I’ve started spotting again. Long story short my young cat died very suddenly and the way I found out was horrific and ever since that happened I’ve had some brown spotting. Has anyone else had experience with stress related spotting or does anyone know what this could be? Im just not sure what to do about it, if there even is something to do.