Period for three weeks. what now?

Patient: Hello,I am on Ortho tri cyclen lo and a few weeks ago missed 3 days of the pill because I left it somewhere for a weekend. That monday I got my period. I continued to take the pill, one each day, for the next few days and it didn’t go away. after 5 days it was time for my placebos, but i assumed since I had just had my period for nearly a week I could skip my green pills and go right to the white. I guess I was wrong because now it’s been 3 and a half weeks and I still have my period. It is coming out much darker than usual and almost dry, like older blood may be. sometimes it goes away for one or two days, but comes back. I am just wondering what is going on and what I should do. I only have three days left of regular pills before I start placebos again.