Implantaion bleeding?

My boyfriend and I always have protected sex. But over the past week or so, I’ve noticed that my breasts are very tender and I’ve had light cramping and in one instance, an acute sensitivity to smell. (Only with fried foods). Today I started my period, which seems be a little bit early. It was a light pink color and the flow is light. I don’t know if it could be implantation bleeding or just changes in my cycle due to stress. (I work and go to school full time). Any help would be greatly appreciated!!