bash I/O redirection - how to append to stderr

I have a script that loops over some big collection of data and performs some lenghty operations. Then i need to sort | uniq -c its output. So to let it know that its alive, I print a dot every N items on stderr (very primitive pseudo progress-bar), so it looks pretty much like this:

for i in {1..100}; do 
    [[ $(( (i+=1) % 10)) -eq 0 ]] && echo -n "." >&2
    shuf -i 1-10 -n1
    sleep 0.1
done | sort | uniq -c

and the output:

..........      9 1
     10 10
      8 2
     14 3
     13 4
      9 5
     11 6
      8 7
      8 8
     10 9

the "progress bar" messes up the output a little - so i was wondering: * is there an easy way to add a nweline to that stderr before flushing that stdout? (probably echo >&2 is all I need) * or remove it ? of course in reeality i dont know wow many items there are (at least not out-of-the box). So i was wondering if this can be acieved by some stream redirection