Welcome, SkinnyGirl! And congrats on finishing law school!
So I've seen other people on 3FC post similar questions, and one of the logical follow-ups is, how accurately do you track your calories? Do you use a food scale? Do you make most of your own food at home or do you eat out a lot and guesstimate the calories? Do you count every bite or taste that goes in your mouth (I tend to sneak tastes of peanut butter and jelly when I make lunch for my kids -- diet killers for sure!). Just food for thought as to whether or not you are actually hitting your calorie target.
Secondly, how many calories are you eating?
If you are counting accurately, and your calorie intake is reasonable (of course, what is "reasonable" is a constant topic of discussion on 3FC), then a visit to the MD certainly wouldn't hurt. Just to rule out thyroid issues, PCOS, etc.
I have found that recording everything I eat (I use fitday.com, which I like; there are several others, including sparkpeople.com and dailyplate.com)
really helps. I can't imagine how many calories I was eating every day before I started recording.
Good luck with all that studying!