Please help. Posted twice w no replies.

So I'm confused if I just had my period or not? So on May 25th, 30th, and June 5th, I had sex with my SO. I'm on the mini pill and have been for several months. I was supposed to start my period in 3 days, but I started bleeding yesterday, which was weird for me because my cycle is usually spot on and I started 3 days early. I thought it was implantation, but it looked like too much blood to be implantation (I'm not even sure if it was "too much" lol) it didn't fill my tampons, but I still wore them. My cramps have been worse than normal and I've been having hip and back pain, which I don't normally have as a PMS Symptom. Now today, I've almost stopped bleeding (light pink). Is this implantation or just an abnormally short period? Thanks ladies! 
Also: I was late on my pill a couple times the last month, so pregnancy is possible and the timing sounds like it could very well be implantation. Just trying to figure out if I should take a test and if so, when.