Please help

I asked a couple days ago but now I'm really worried. I was 5 days late on Saturday last week ( the 24th of June) but my period came on the Monday after that weekend but it hasn't stopped. It started off really REALLY light, a very bright pinkish colour but now it's been 9 almost 10 days and it's gotten heavier and darker. I don't know what to do, this has never happened before. I'm 19 and sexually active and hoping to get to the docs sometime this week but I'm really starting to worry.