HELP! PERIOD TROUBLES

Right! So I've been on the pill for 2-3 months now due to having really strong and painful periods and the pill helps bring that down abit, when you miss a few pills it can make you bleed abit and fuck up your flow? Yes that's happened once in that time and it wasn't recently, I got my period on the 17th this month and I've still been bleeding ever since but it doesn't look like regular period blood? It's black/brown and slighting gooey 😳 I don't know what's wrong with me can someone relate to me or help me with this?