My daughter is 7 weeks old she has been on S26 ...

My daughter is 7 weeks old she has been on S26 and was really unsettled between feeds. the doctor suggested changing her formula to Nan or Karicare. I have changed her to Nan Gold but not the HA one she seems even more unsettled constant wind, squirms, wimpers and generally unsettled. I would appreciate if anyone has any suggestions?