But Nephew was more than six months old, he was sleeping through the night, and he was eating solid food in addition.
I went on a tour of the Internet and found this page
http://www.loveyourbaby.com/fertility-while-breast-feeding.htmlfull of interesting things. I also found a site I don't have access to that spells it out in a scientific journal. I did see the first page, which listed some of the info cited on the page we all have access to.
In case you have a way to get in, here's the scientific paper:
http://links.jstor.org/sici?sici=0032-4728(199103)45%3A1%3C91%3ABAFACA%3E2.0.CO%3B2-3
Interestingly enough, breastfeeding is very effective in preventng a second pregnancy too close on the heels of Kid #1, but there are ways to reduce the effectiveness. Like all birth control, you have to use it properly.
As a side note, I've got a friend who is trying for Kid #2 and Kid #1 is already 2 years old. Still breastfeeding, but no attempt to wean has been made, she gets mom's milk any time she wants it, and mom doesn't dare go out and have a night out with her friends that doesn't include the child. Can you say screaming fit until mommy appears? I knew you could.
On edit: the link to the scientific paper messed up and my browser isn't cooperating to let me fix it. If you want to check it out, you can paste it in your browser address window. Sigh.