Mid-cycle bleeding...neg OPK

Amanda • Trying for baby #3!
So for the last two days I have had very light spotting. I thought it was an indicator I was ovulating but then this evening I got a very negative OPK. Almost no line at all. I have a very regular cycle 29 days long. Has this happened to anyone else? Could I have missed the surge? I am really worried I am not ovulating at all. Could the strips I have be faulty?