My husband purchased me a nice Pajama Set for Christmas.  I always get XL in Pajamas to make sure they are loose and plenty of room to lounge.
At first, the seller made an error and sent a Large.  When we received the XL they were very tight and went below the stomach.  This seller gave no refunds but kept sending me larger and larger sizes.  I went on the website and noticed that a lot of pajamas now had pajama bottoms with no elastic and they started below you stomach(or belly).
I kept the top which fit fine.  I finally found this beautiful pair of Pajama Sleepwear which is confortable and goes great with my top, plain black (goes with a lot) and fits great!