So I did a little research in shunt resistors. I considered them but never know that there were some kind of "ready to use"-solutions.
I found this one: INA219
If I would replace the 0.1 Ohm resistor with for example a 0.5 Ohm resistor, then I should be able to measure from -6.4A to +6.4A. And this method would even be 12bit ADC instead of 10 ADC.
Altogether this should be a better method to measure the pulse current?