If you can keep that up every day, you'll be fine. My problem the last few days was that I couldn't write some days, so I fell further and further behind. Last year I won because I threw in several 7000 word days in a row. This year I'm getting up a buffer (I'm almost to 12k - keep in mind that this is my fourth year) in the first week, when it's easy. Easier, anyway.
Bring around a notebook with you, and write a little bit when you get a chance - even if it's just 100 words. Write extra on weekends. Think of writing as a reward for getting other work done, and you'll probably do it a lot more. Even if you only get one or two days ahead by the end of this week, that will give you room to breath in week two when, chances are, you'll really need it.
Basically, don't stress too much but try to be prepared for missing a few days. And on that note, never let yourself miss more than two days back to back - it will be very, very hard to get back into the habit again.