Don't Know What's Going On

Okay I was told that I should take a pregnancy test because I had sex in September, Got a negative pregnancy test and got my period in October so I thought I wasn't pregnant but now its November and I haven't got a period and got a negative test AGAIN. So I'm assuming I'm not pregnant but where is my PERIOD. Im starting to believe i cant have kids cause i have had unprotected sex nd havent got pregnant i think i done some damage to myself... Ik I shouldn't want a baby at 16 but I been having baby fever and was so happy to the fact that I might was pregnant in September and October but now I'm sad but happy cause I have career goals and all that but I see every other girl with a baby and I want one... Ik never be a follower I'm not going to be nomo I need and want to focus on myself you know, I want my mother to be happy that I'm pregnant one day not sad or mad.. Any advice???