My boyfriend and I were just fooling around a week ago. He fingered me and he might have had some precum on his fingers. No cum, though. My period was due on the 8th of October. But 6 days after the incident with my boyfriend (on the 4th of October), I started bleeding. I thought I had started my period. But it stopped after a few hours. It has been 2 days today, and there is no bleeding anymore. Additionally, I had just started a vigorous exercise routine 5 days before the 4th of October. Could I be pregnant? Or the bleeding was only due to some other hormonal changes?