I need some advice talking to my single dad abt my period

So ive had my period for going on five years now (i turn 17 in february and got it when i was 12) and its always been irregular. I figured it was because i was still young and it takes time to like create a schedule and become regular. but over the past like year its gotten concerning. it still hasnt become regualr and sometimes i can go months without a period or when i do have one, it lasts for like two+ weeks. the bleeding can range from super light to really really heavy. I want to see a doctor about it but its just me and my dad and i dont know how to bring it up to him because it's something that im not good at talking about. can someone please tell me what to do?

update: i went to an appointment recently and explained the problem and was told to "just drink more water"😐. i have another appointment coming soon so maybe ill actually figure out whats wrong.