opk help

I usually have 24-28 day cycles. last month I started around cycle day 21. I had super light brown spotting for 5 days and than heavy spotting for 5 days, a total of 10 days. typically my period only last for 5 days so my cycle was way off. last month was the first month of ttc so I'm a little disappointed things are suddenly off. I've been tracking my ovulation for over 6 months. I typically get my positive on cd16. I'm now on CD 19 and I'm finally getting a positive opk. I should start my period in 5-9 days. Does it look like I'm ovulating or could I be getting an lh surge because my period could be close?