It can take 4 to 5 days for your actual milk to come in. However, your body is producing colostrum right now which is exactly what your baby needs!! Your baby doesn't need a lot of it either! It is very high in nutrients and baby will get all that they need from it!
Mine was in by day 2 with both babies. You have to nurse a lot to signal your body to make milk. The more nursing, the faster it comes!