Welcome! Your just about the same size as me (5'2, sw 172), I'm on day 8 and I've lost 10 pounds so far. I am pretty gassy, still, and it sucks but...10 pounds. The medifast meals weren't enough for me those first few days...I was super hungry, but now they fill me up, I'm never hungry until it's just about time to eat! I didn't believe it would happen, but it did!
As long as your not going over your daily L&G portion, it's fine to split them (I just had a LONG talk with my coach about this yesterday, the portions were too big and I wasn't finishing them, she said I had to...so I guess I'll split it today!) Are you exercising? That could be a reason your not losing...you shouldn't be starting any new routines and should cut current ones in half during the first 3 weeks. Otherwise, it sounds like your doing it right...stick with it a few more days and you should see results.
If you go on the medifast website where you log all your food, it will tell you exactly how many carbs and cals you had each day. I use that to help make sure I don't go over 100!