Brown periods. Please help.

Okay so I'm on the birth control Microgestin Fe 1/20 due to irregular periods. I was on it for 9 months, then off of it for 5 months. And now I've been back on it for 7 months. The past 2 months I've had periods that are small brown clots with very very little blood (like only when I wipe). Everything else is normal like my boobs hurting before period and they stop hurting when period starts. All my symptoms are the same as before. I don't believe I am pregnant but I'm always paranoid about my body functions changing. I have missed one pill in the 3rd week in May but took it as soon as possible the next morning. And implantation bleeding hardly EVER happens. So don't even say that