It's definitely normal, especially if you didn't use it much within that week. Patina develops from sun exposure, air exposure, dirt, and oil from your hands so if it isn't used a lot within that week, it isn't getting a lot of exposure to the above mentioned things and therefore takes a bit longer to develop a honey patina. Just be patient (or sunbathe your bag) and soon you'll have a beautiful patina to your liking!
My mom's alma from '96 (if I'm not mistaken) only has a touch of patina and it hasn't even spent a day outside of the dustbag!
Absolutely! It depends on the sun's rays. When I used one of my new bags during the winter (I carried it 15 times so far), the vachetta tanned only slightly. That's because UV rays are not as strong in the winter. Contrast that to the summer when I carried one of my new bags 5 times and it got tanned very quick.