Implantation Bleeding?

It has been a few days after the fact, but Friday, April 1 I had some cramping in my left side. I thought it was just ovulation cramps, which I usually get but Saturday came and I went to the restroom, when I looked down I had cm and it had strings of blood in it. It had only happened that once though. It was 15 days after my last period had ended and it was the week I was supposed to ovulate. Could this be implantation bleeding? Please help!