Basically, I'm really worried.?!

For the past few months, can't remember exactly how long, I have been experiencing weird blood clots about 1-2 weeks after my period. Its really odd. I'll start getting what looks sticky and dark colored, then it gradually turns into light brown bleeding. I am currently taking Lutera Birth Control. Could this be serious? I am going to the doctor soon, just have to figure out some family issues first.
After the light brown bleeding, it leads into my period.

I do miss pills sometimes, by the way.