Likely "in transit" or "production complete". Mine was only in that status for a very short time as it took less than a day for Tesla to move my MS down to my SC about 450 miles away.
As you'll see in some other threads, "in production" is a very broad status that represents everything from the point after order confirmation where Tesla is determining parts and actually scheduling the physical build to begin -- to the actual construction, quality assurance, etc. to the point where your MS leaves the plant on the way to your SC. It can be "in production" a matter of days or weeks, so while I know it's hard to wait, this is the status you're most blind to actually what's going on inside Tesla. Good luck on the wait!!!