Confused

I got a serious question and I really hope I’m not the only one. I just turned 21 and have been trying to conceive for the past year (I know I’m young still but I feel I’m ready, I even got my own place) anyways, growing up I noticed my period cycle is very irregular. Lately I’ve been watching close. September 2017 I got my period then I haven’t gotten it until January 2018 and up until now I still have not gotten my period. I have taken multiple pregnancy tests but they all come out negative. I’m feeling really defeated by it.. is their anyone else that has this problem?