14 day period

So I’ve been on birth control for about 2 years now. I haven’t had any changes in dosage or brand. I usually get my period every other month for about 3-5 days VERY light but right now I’m on day 14. I had my usually period for 4 days very light as expected and it stopped for a day and now it’s back and doesn’t seem to flow. Once i pee and wipe i have a very heavy amount of blood but none ever ends up on a pad and barely any is on my tampons. But i know for a fact the blood isn’t in my pee. Anyone have any ideas?