What’s happening?

So this is what is happening with me and I would like some opinions. I understand no one here is a doctor, and if it continues I will see one, but in the meantime just wanted opinions. Cycles are still somewhat irregular after having my boy 6 months ago, but getting better. Started what I thought was a period 2 weeks ago (11/26). It was unusually light and only 3-ish days. However, there was an incredible amount of stress at that time. Today, I noticed pelvic cramping and red spotting. I’ve never had cramps or bleeding in between a period before. I have no gyno issues (no PCOS or cysts or anything). Likelihood of pregnancy is slim to none thanks to an IUD. Any ideas??