Is there a possibility I might be pregnant but still having my periods?

I am a 17 years old girl and I'm pretty scare about this..

So this is my story

About three months ago I had sex with my boyfriend.. who ejaculated inside me, USING CONDOM...  The condom was ok, as he said.. but then a problem occurred.

Two weeks after that I was supposed to have my period, but it was late. I panicked.. but fortunately after 2 days it began. As I can tell everything went as it was suppose to be, but I was still scared and my stomach continued to hurt afterwards.. About a week later I got a home pregnancy  test, and it came negative. So I was relaxed and my pains were gone.. The next month I had my period right on time, but I had some stomach pains between periods.. like in the second or third week. My stomach still hurts from time to time.. I first suspected it's because I'm not eating well but I don't know... I'm now having my period (second after the pregnancy test) and it's normal.

I'm not really tall for my age, not fat.. but kinda complemented (don't know if this is the right word) and I have a stomach

So.. is there a possibility I might be pregnant but still having my periods? :(

Thanks for reading..