Getting hair transplant while hair is thinning ? (photos)

At first I thought my hair was completely gone but When i look closely I have really small baby hair in areas were it looks bald. I don't know why it does not grow but I can tell there is small hair and not gone. And now I am wondering if i get a hair transplant will my hair still fall out or should I follow some advice I got from a friend and just wait until all the hair that has to fall out falls out and than get a hair transplant . And thank you in advance for any advice, suggestions