Is it the end of the line for you , find out how many children are still in store for you in three easy steps . Our calculator takes your age , length of your menstrual cycle and the age of your puberty , and gives to you an approximate average of possible successful pregnancies based on your fertility years remaining . This takes into account the average child gap and the period of breast feeding providing a minimum period of natural contraception. This app does not take into account multiple pregnancies such as Twins, Triplets or quadruplets, only singleton pregnancies.