Brown spotting on CD 14?

Just now I went to the bathroom and had quite an amount of brown spotting on the toilet paper. I just had an HSG done, but that was on like CD 4. I stopped clomid last month, so this is my frist regular cycle afterwards. What could this be? I never spot inbetween periods, and I ovulate different times almost every month (cuz of PCOS), exept when I was on clomid (which was about cd 19 for ovulation). Please let me know what you think.