IVF is not a one day process, it’s a series of procedures put together. Ideally, it takes 10 to 14 days for the eggs to grow. Once that happens, couples are called for extraction and fertilisation of eggs. After this procedure, the couple would be asked to visit again within a couple of days to implant the embryo into the uterus.
For couples below the age of 35, eggs are quite healthy; many of them may get success with conception at just one session.