Female in heat and what she needs when she becomes pregnant

Question
I have a female Shiba Inu who is in heat right now, she is 8 months old. How long will she bleed and can she get pregnant from day one until the end of the heat? We do have a male Shiba Inu and we have kept them apart, we dont want the female to get pregnant until she is older. When she does get pregnant does she need a special diet or vitamins? Also everytime the male gets near her she growls at him.. when the time is right will she actually let him mount her and how do we get that to happen? Before her heat she never growled at him before, I just figured she is moody :) Thank You

Answer
She will be in heat up to 28 days,  I know of dogs who have bred on the 21 day and gotten pregnant.   But normally the fertile time is around the thirteenth day.  Do not be fooled by the recession of bloody discharge.   That is the time they are most fertile.  Count from the first day you saw blood and keep her away from the male for about a month to be safe.

She is probably growling because she is not ready, so be careful, if that extra hormone gets there, she may turn around and mate with him.  On the other hand, she just may dislike him.  I had a female that refused to breed with a male, but liked a different male.  They have feelings too.