(Taking you seriously) Try keeping a log of your estimations and the actual time taken. Write down both the original two day estimate and the extended 11 day on

(Taking you seriously) Try keeping a log of your estimations and the actual time taken. Write down both the original two day estimate and the extended 11 day one. Then after a few months you should have a good set to look at and hopefully convince yourself to believe your modified estimates. Or how to adjust your formula to be more accurate.