period drama

I am 17  and have only had my period about 7 times in the past year and a half and none before that. I am very irregular. is there something wrong with me. I am not heavy when i do get mine. i was late 16 when i got my first one and feel more self conscious about it b.c its still pretty new. also i dont use tampons but want to start but don't know how. i have read the instructions in the box but it kinda hurts when its in. what is wrong with me i feel immature that i don't wear tampons and don't get my period.