I THINK IM PREGNANT!!!????!!! HELP?

I FIND YOUR QUESTION VERY INTERESTING AS I AM WORRYING ALMOST ABOUT THE SAME THING IVE NEVER BEEN PREGNANT BEFORE BUT MY BOYFRIEND MED IN ME TWICE IVE BEEN FEELING VERY TIRED AND SICK MY PERIOD ONLY LASTED TWO DAYS AND WHERE VERY LIGHT THEY USUALLY LAST FIVE DAYS CAN I TOOK MY FIRST HPT BUT IT CAME OUT NEGATIVE:( CAN I STILL BE PREGNANT:)