Period problems

i’ve been on my period since the 9th and it’s been black since then. Like not even dark red is been black and not really blood either it’s like black clot like stretchiness. It’s not been any real blood or even dark red one day since then. I’m on birth control, and have been for years. Is this something to worry about? Do not reply any rude things like We ArEnT dOcToRs either thanks😊