ayy man, it's just one of those things in life.
don't freak out if you do, it'll be fine.
literally all you do is bleed for a few days, you'll have to change every now and then. you might cramp still, or be a bit emotional tho.
but for all I know, it could just be hurting for other reasons.
Mine started when I was 11 so it’s not that bad, my advice is to get some small pads if your just starting it and get bigger ones after 1 or 2 days, that’s how mine works