Could there be a fair chance?

Ive been going through changes within my body, and by me being a young adult i wouldn't expect anything but growing up. I've been on BCP, but never manage to continue them like i suppose to, it's been a while. I always feel like I have to vomit all times of the day, im always tired and lazy, and become very irritable. Im going through my normal period but before, i've had lots and lots of syptoms then when it actually came they were still there but they weren't as furstrating. I have gained weight within a couple of weeks. I'm talking about coming from 116lbs to 137-140lbs rapidly. I never thought that I would be pregnant at the time because I'm continously playing the blame game,just growing Lol. And yet I refuse to go to the doctor to find out yes or no, but I've also read alot of articles about women being pregnant and still having a period that would last or sooner or later end. Could I possibly be pregnant or just growing.