I think im pregnant plz help me figure if i am?

see im 15 and i was with this guy for about a year and a half but we broke up we had in december and we had unprotected and now i think im prego like now im sleeping more often and i was like 115 lbs with no rolls just a flat belly but now i got rolls like when i slouch down in a chair like the top part of my stomach just goes in and the bottom pokes out so... and when i lay on my back with my shirt off like this pumping on the bottom of my stomach just happens idk if it done it before but now its like freaking me out like i got a extra heart beat and im gonna try and get a pregnacy test next week idk how much it will cost but if i am im uming im due sometime this month so help me im not showing or no symptoms have been discovered except what i just found out and now i just have stomache pains when i go to school in the mornings like growling and etc..but help me out i dont want my parents to find out yett until i find out they will probally kill me and the boy dosent want anything to do with me so idk what to do if i am help me dont need no lesures just help and im probally not getting a abortion