I did go to the doctor a few weeks ago regards the long cycle and the brown period. They told me they couldn't do any blood work as they wouldn't know which day to test hormones due to my irregular cycle.
It can be really confusing when we are irregular. I've been there. Apps help but not that much when irregular other than tracking days we spot, how many, days we bleed and how far between. That's helpful to know but when irregular really can't help us predict anything. If you don't want to get pregnant, be sure to use condoms. However, what you describe means I think it would be hard to get pregnant. I would go to your doctor and have some blood work done. You sound like your hormones are out of whack. Brown spotting for long periods of time are an indication of this. Let us know what the doctor says! good luck