Is this bedbug or book louse?
The pictures aren't very clear, but I would put this down as a book louse, not a bed bug nymph, as the body is quite elongated, which is atypical of the bed bugs and more typical of book lice.
Book louse:

Bed bug:

Courtesy of  bedbugger.com.
Check out also this page from the University of Minnesota Extension; the picture nicely matches the photo you posted in body shape.