If you are still bullish,, why not sell the march 500 call and buy an APril 530. But do it soon, not after they take out that last 3 or 4 weeks of time premium from the March.
Look up option time spreads (and diagonal spreads). When you put on a time spread against your long call, you are really just converting your position to the April. But thinking about the time spread will give you an idea of the impact, versus doing nothing.