Could I be pregnant?

Me and this guy had sex about 1-2 weeks ago. At first we didn't use a condom then after awhile he put one on and we continued. A couple days after I started bleeding. My period isn't due for another week or so. It began a little heavy then immediately after two days , went super light and was shorter then my normal period. I haven't been feeling too well. Could I be pregnant or just paranoid?