She’s still going….

I normally have very heavy periods (double tampons and a pad). I also bleed between periods and need a tampon then too. Well this time I started my spotting on the 17th and it kinda didn’t stop. It just continued into a heavier period and now I’m on Day 17 of bleeding. I went through a whole box of ultra tampons. My mom said there’s no immediate health risk, but it’s an indication that other things are not working properly. I have to get a hormone test anyway, but have you guys ever experienced this? Why is it lasting this long?