jasonsteph:
do you think the LED's code will not interrupt the SERVO's code. even for a millisecond?
Yes. It will interrupt the servo's code for a few microseconds. And for most processes that Arduinos manage - swinging a servo arm, turning a LED on and off - a few microseconds is effectively nothing.
(Please try to not ask negatively phrased questions in future when you are dealing with computer programmers: we detest them.)