AF never shows up, now this!?

Hannah
Last month (June) AF never arrived. I had about 2 days of spotting, but that was it. I took 4 pregnancy tests over 2.5 weeks all BFN.
Now, 3 weeks later, I began spotting about a week before AF should have been due. After 2 days of spotting, it turned into full AF. Now it's been well over a week with no end to AF in sight. 
What is going on?
Has this ever happened to anyone else? 
I have PCOS, but have always been pretty regular. Nothing like this has ever happened.
Please help!