I'm worried I'm pregnant.

My nipples have been sore for about a week and that's never really happened and I'm kinda worried it's a sign that I'm pregnant. My boyfriend and have just started having sex and we've used a condom every time. I've also had my period multiple times since we've started having sex and they all been an track. But my last period was only about 3 or 4 days and it's usually about 5 or 6. I'm worried I might be pregnant.