Pcos is definitely confusing to figure out periods, pregnancy, hormones. Yes, with PCOS, your ovulation can be random. It can mean you tested too early or it can mean you are just late and it has nothing to do with pregnancy too. So hard to judge! Many women with pcos require intervention to conceive such as taking clomid or taking metformin. These options can be available to you if you and your doctor decide to go this route. I have friends that got pregnant when taking these medications. Brown blood is old blood and is really more spotting than a period. It is likely you haven't had a period when you've had days of just brown blood without any red. :>(( Personally, if it were me, I'd go see your doctor. I'm sure you have and have discussed your wish to conceive but I'd up your game here. They can do a blood test to check if you are pregnant. That will give you an answer on that. And then, they can start working on optimizing things for you to have your baby. Once you get regular, trying is definitely easier. Adding things like progesterone may happen because a lot of brown spotting can be a lack of progesterone as well. So, they really need to do lab work and get a read out of your hormones. Once you are regular, you can take your temperature every day. Do it first thing in the morning, I kept a thermometer by my bed and charted it. THIS my best tool to know when I had actually been successful in getting pregnant. AND, to know if I actually ovulated. Your temp will rise when you ovulate about a degree. It stays high until you get your next period. OR if you are pregnant, it never goes back down. The two times my temp didn't dip back down were my two pregnancies. But it is a great way to understand your body. Also, if your temp never rises --- you will know you have not yet ovulated.
But for now, I would go tot he doctor, get a baseline everything, discuss next step for conceiving (and also find out if you already did this time or not!) Come back and let me know!