Is this old blood?

Noona • 🇱🇧💍👶🏻👶🏻🇬🇧

I am 15wpp. I had my baby on the 22nd August, I bled for 5-6 weeks, then on the 5th of November I started spotting dark brown. I was on the mini pill during this so I figured that was the reason as the last time I was on it I was constantly spotting.

Fast forward to the 26th of November, I stopped the mini pill and had a copper coil fitted. 2 days later I come on a proper period which lasts 7 days, but now I have this... is this all normal or should I be concerned? I have cramping from time to time.