sensitive stomach

me and my boyfriend had sex and our condom broke . i was on birth control ( i was taking it perfectly ) and i took a plan b 30 minutes for back up . my expected period for my birth control never came . i took a pregnancy test eight days after the first day of my missed period which was clearblue and it was negative . ever since i took the plan b , i’ve had light cramping ( which was been over a month ) and recently , every time i push on my lower stomach , it’s tender . am i pregnant ?? i am way too young to have children !!