positive opk but bleeding???

Jennifer
Help please! I had a high fertility opk on cd11. Then I started spotting. It turned red and I decided it must be an irregular cycle(never have those!). It never turned into a real period flow -just heavy red or brown spotting. Today is day 13 and I just got a peak fertility on my opk. Do I still try or am I out this cycle? 
Oh and I had bloodwork done on day 3 (dr wanted to see what was up since we are having trouble TTC) and it was perfect! I'm so confused bc it seems like my hormone levels are perfect but I'm bleeding anyway :( any advice or theories?