My eldest bitch is in season and she is only taken out just as its dropping dark and only on the lead - that way less people and dogs are about where we take them and keeping her on the lead is for her safety incase a male appears etc....
Do watch for males jumping in the garden and your girl jumping out too......
They can conceive at any time .....it all depends on each dog - I have known dogs catch on in the first few days and also known dogs who have over a week after bleeding has stopped so there is no rule of thumb with it