Hello. Brown spotting is old blood and can often be really meaningless and just happen. Hormone imbalance can cause it as you've read. Early pregnancy can have spotting issues. But this would be more likely that you didn't really have a period during your last cycle and were actually pregnant. Or it's implantation bleeding (which is actually pretty rare). But at 14 to 15 days in your cycle, you are just now ovulating.
Which is a long way of saying that it is hard to say what is going on. When your period is due, take a test. I'm sort of doubting you are pregnant but if you've had unprotected sex last cycle or this, it could be. When's your period due?