You really can't tell that with regular level II even during regular hours. If you are using ihubs tool, it only assumes buy/sells on whether the print was at the bid or the ask. You don't have level II for after hours? YOu can use this to see prints: http://www.nasdaq.com/quotes/after-hours.aspx but it doesn't show level II.
Register for free to join our community of investors and share your ideas. You will also get access to streaming quotes, interactive charts, trades, portfolio, live options flow and more tools.