LH surged??

Just wondering if anyone has had a similar experience: Had a lighter than normal AF last week. Started testing for ovulation the day AF ended (Sunday)—early I know, but I wanted to track progression. To my surprise, my LH has been pretty high (not quite positive yet though) from Sunday through today. hpt from last night is negative (see pic). Could I be about to ovulate so early?? Or is there something else that can cause LH surges??