You want to know when will you conceive and how many children. I have never heard of a formula by which you can calculate the number of children you might have in Astrology. Yes astrology can say how potent is your fifth house and this will give you an idea or indication of how happy you will be with your children.
In your horoscope you have a 43.44% strength for your 5th house and so you will enjoy the company of your children to that extent.
In these days with all the family planning etc. how can we say how many kids you will have and how many will you abort due to various reasons which are very common. And you can even arrest the birth of a baby using artificial methods. Astrology will go for a sixer if we start predicting on these sort of questions.