Ullo, I was wondering for those who have done...

Ullo, I was wondering for those who have done it : if you continue breastfeeding while you are pregnant what happens with Colostrum when your next baby is born (if you continue to breastfeed the first one)? Does it change and then change back? If not, does that mean the secound baby doesn't get any and gets milk straight away? I spose it would be hard to tell what's coming out if there's a baby clamped on there but if anyone could shed some light on this as it has been bugging me. (Not that it is an issue for me but I am just curious) Ta Muchly.