Ovulate twice??

Hi ladies, I need some advice please. Looking at my bbt graph, it would seem that I ovulated twice in one cycle - I swear I had all the symptoms for ovulation at my first temp dip and although I didn't get a clear positive on my opk during the first dip, the lines were pretty dark and FF actually gave me crosshairs right after that...but then the second dip happened and I got two peaks opk's on consecutive days. What's going on? I've been off the pill since Dec 2015.