I've been on my period off and on almost for three weeks.

What do you mean by "off and on"

I came on the 19th of December.Then it went away.Came back on the next day.Went off again.Came back on the following day and so on.When I wipe it s just still lingering around.I failed to mention that I have systemic and skin cantaneous lupus.I have had irregular periods but not like this.I also had 2 have one of my ovaries removed.I am also on Birth Control pills.