Well, alright Hillary. Making decisions is hard. But I have great news for you! One thing you no longer have to decide on is whether or not you want to concede the Democratic nomination for President of the U.S.
You see a concession happens before the end of a contest. You lost. There are no more primaries, no more caucuses, and not enough delegates left to make you the nominee, even if you managed to change the rules about Michigan and Florida.
If two baseball teams are playing and the team up for bat has more points at the bottom of ninth inning, the other team doesn't concede it loses.
Now, I understand the confusion though. In almost any primary I can think of everyone aside from the winner conceded before the contest was over. For example, Mitt Romney conceded to John McCain even though he still had a fair shot at the Republican nomination.
The reason they do this is to prove that they are loyal members of their party. For example, if you were a loyal Democrat, you would have conceded after the Texas and Ohio contests because it was clear that it was almost statistically impossible for you to win.
So the primary is over and you lost. Oh wait, there is one decision for you to make. Whether or not you would like to endorse the Democratic nominee. Of course, if you were a loyal party member, this would be an easy decision.