Mid cycle bleeding

I bled for 6 days midcycle. It was like a light period. It was enough to put in a menstrual cup but it was only like a fifth of the blood that I usually have during a period when I would take the cup out. It was a little more than spotting but not exactly full flow. It bounced back and forth - each day was different. It went from heavier to barely there to heavy again several times. I've never had midcycle bleeding. I haven't had a real period on my own, probably in my entire life. So to start bleeding without Provera shocked me. I had been on Metformin and Actos for almost 2 weeks weeks when I was on cd19 when I noticed a tiny bit of blood. I'm on cd25 and the bleeding stopped today. Did I just have a light period mid cycle? What even was this? Is that too much blood to be a pregnancy symptom? Could that mean I had a chemical pregnancy? I'm just so concerned as this has never happened to me.