I think everybody's different and it also depends on the chemo drugs you get.  The first time, I had breast cancer, I used the cool cap and didn't lose much hair on my head.  I lost arm and other hair almost immediately and I lost my eyebrows and eyelashes when I finished FEC and went onto to  Docetaxel immediately afterwards.  The brows and lashes came back, albeit a little less full than before but still Ok.  Second time around on the same drugs, I had no cool cap and my head hair went at the same time as everything else except for the brows and lashes which went again on the Docetaxel.  This time, unfortunately the brows did not return at all so I have just bitten the bullet and I got them tattooed - not painful and I have better brows than ever before!  Don't lose heart and keep the faith - you will get through this!!!!!