Missed my window?

Hi all. I had about 6 days of brown spotting after my period (which had been 5 days late, really unusual) so I thought that might delay ovulation. I did test around the time I would normally ovulate, but missed one day. All came back negative. Did have a couple of days of ewcm so made sure to BD just in case. Predicted ovulation was around Sept 3. Last night when I wiped I had creamy, very pale brown, discharge. AF not due until Sept 18. Don't know what's going on!!