Someone help me !!!!!!?

i haven't seen my period since june this year and this is september same year , i have neva had in my life ,when i told my mom she started to cry that i am pregnant , i never had am still sixteen is this some kind of change or what am not really happy about this , am scared , am not ready to have a baby without even having can that really happen ,i have not gone to the doctor 's or had any pregnancy test , and the freaky thing is my stomach is kind of looking big and bigger and i feel tired most of the time ....AM REALLY CONFUSED ....HELP ME PLS