I've had my MacBook for about 2 1/2 weeks, and pretty much since the beginning, the charger has been a little odd. About 60% of the time, when I plug in the charger, it won't turn green/orange, anything. I have to unplug it 4-5 times before it recognizes that it's been plugged in, and it starts charging without a problem. I've tried a few different outlets but this happens at all of them. Should I wait more than ten seconds to see if the charger recognizes that it's been plugged in? Any advice? Thanks.