Robert is right saying that options' prices are affected by implied volatility but is wrong saying that you have to look at the VIX index. For two reasons:
1) the VIX index is for S&P500 options only. If you are trading other options, it is less useful.
2) if you are trading an option that is not at the money, your implied volatility may be very different (and follow a different dynamics) that the VIX index.
So please look at the right implied volatility.
In terms of strategy, I don't think that not doing anything is a good strategy. I accept any point of view but you should consider that option traders should be able to adjust positions depending on market view.
So you are long 1 call, suppose strike 10. Suppose the underlying price at the time of entry was 10 (so the call was at the money). Now it's 9.
1) you still have a bullish view: buy 1 call strike 9 and sell 2 calls strike 10. This way you have a bull call spread with much higher probability of leading to profit. You are limiting your profit potential but you are also reducing the costs and managing the greeks in a proper way (and in line with your expectations).
2) you become bearish: you can sell 1 call strike 9. This way you end up with a bear call spread. Again, you are limiting your profit potential but you are also reducing the costs and managing the greeks in a proper way (and in line with your expectations).
3) you become neutral: buy 1 call strike 8 and sell 2 calls strike 9. This way you end up with a call butterfly. You are almost delta neutral and you can wait until your view becomes clear enough to become directional. At that point you can modify the butterfly to make it directional.
These are just some opportunities you have. There is no reason for you to wait. Options are eroding contracts and you must be fast and adjust the position before time starts eroding your capital at risk.
It's true that buying a call doesn't make you loose more than the premium you paid, but it's better to reduce this premium further with some adjustment. Isn't it?
Hope that helps. :)