Am I pregnent or are there any other logical explantions?

I have always been Irregular with my periods, but now that Im sexually active Im scared every day Im late. My boyfriend and I are always super super carefull when having intercourse. We never have it unless we have a condom and are constenly checking if it breaks during, and then check it for holes when finished. I am almost 10 days late which is strange giving the fact i have been pretty regular the past few months, I have had somewhat bad acne for me the past couple weeks and my nipples are sore and a couple other slight symptoms and Im 19 and kinda freaking out.