Unlikely if you usually see ovulation later than this on the whole, but if it varies all the time, or if you usually see ovulation around the time of your darkest OPK so far then quite possibly.
Like I have a fairly good idea when I ovulate, usually CD11 or CD12 each cycle with little variation. I frequently see darker OPKs immediately after af, immediately before af and sometimes randomly during my lp further away from due af so it's completely possible. It depends on your own averages, if you can pinpoint them