Late Periods

okay so im 16 and I just started having sex like 3 months ago. We always use protection. Last month when I was supposed to come on, I was late by a day (I know its normal to be late sometimes). This time so far im late by a day but im experiencing the things that usually happens when im about to come on and I still haven’t came on...these things including headaches and cramping. Idk why I keep being late though, im young and im worried...im scared to talk to my mom or anyone else, can someone let me know something