How do I select two weeks ago in MYSQL?

I have a report that is driven by a sql query that looks like this:

   SELECT batch_log.userid,
         batches.operation_id,
         SUM(TIME_TO_SEC(ramses.batch_log.time_elapsed)),
         SUM(ramses.tasks.estimated_nonrecurring + ramses.tasks.estimated_recurring),
         DATE(start_time)
    FROM batch_log
    JOIN batches ON batch_log.batch_id=batches.id
    JOIN ramses.tasks ON ramses.batch_log.batch_id=ramses.tasks.batch_id
    JOIN protocase.tblusers on ramses.batch_log.userid = protocase.tblusers.userid
   WHERE DATE(ramses.batch_log.start_time) > "2011-02-01" 
     AND ramses.batch_log.time_elapsed > "00:03:00" 
     AND DATE(ramses.batch_log.start_time) < now() 
     AND protocase.tblusers.active = 1
     AND protocase.tblusers.userid NOT in ("ksnow","smanning", "dstapleton")
GROUP BY userid, batches.operation_id, date(start_time)
ORDER BY start_time, userid ASC

Since this is to be compared with the time from the current payperiod it causes an error.
Our pay periods start on a Sunday, the first pay period was 2011-02-01 and our last pay period started the 4th of this month. How do I put that into my where statement to strip the most recent pay period out of the query?

EDIT: So now I'm using date_sub(now(), INTERVAL 2 WEEK) but I really need a particular day of the week(SUNDAY) since it is wednesday it's chopping it off at wednesday.