This is a short post, but I stumbled upon the Wonder Weeks book when Caroline was about five weeks. She had become really fussy in the evenings, very clingy, fought sleep (still does some) really bad, and her overall demeanor was just not happy. So, like any mid-twenty year old, I Googled it and stumbled upon this book. I actually haven't read the book but downloaded the app.
It basically explains that there are certain weeks that babies go through developmental changes. These are called "stormy" weeks and she was going through one at five weeks. And then, almost overnight, she was a completely different baby. She started enjoying being in her swing more, using her activity mat more. She was smiling more and was really recognizing faces more.
She follows what the book has outlined to a "T" so far. She went through another stormy week at week 7 and the changes we see in her now are "talking," smiling back when we smile at her, she leans forward when sitting up (early sign of grabbing at something), and batting at objects.
I would recommend the book or the app for any new mom! It reassured me that her stormy, or fussy weeks, are just temporary and when she gets through them, she is a much happier baby!