What about during the editing process? We risk taking out necessary information. If you have to trim the MS back due to WC be selective and be careful. Don't take out words simply to reach a quota.
So am I saying don't worry about word count at all? No. I'm saying don't obsess over it and I'm sure you'll find your final MS will fall within the predefined parameters for your genre. It's like that saying, "worrying doesn't do any good". In fact when it comes to stressing about word count your story's at stake.