rabbitpiggy,
Sorry that I have to reply in English, as I am on my trip with my family and my sister, so I did not bring my chinese writing board with me.
About the pillow, over one year old infant will be suitable to use it.
Just choose the style which is as normal as the one you used in your bed, DO NOT CHOOSE the one which is flat in the middle, as if your child with his/her bottom up position, s/he may easy to suffocate. ok?
Also, need to put the pillow case over the pillow, choose the 100% cotton with more than 200 threads sew. that will be good enough to prevent allergy development. By the way, remember to wash it weekly -bi-weekly.
If you do have time, need to bring it to the outdoor, like next to the window, let the sun shine to cover it for about 30min.
About the pregnancy during breastfeeding period, you can simply get the test set, which you just lick on the tester, and it can get the result from your saliva to find out when you are easier to conceive. Or you can take the temperature, you need to buy a special themometre which provide 2 digit behind Ozeo-->like 36.98C/ 98.56F
You can continue to breastfeed your son, no problem, but I would suggest if you really planned to have another kid, you better choose a period to stop breast feeding your son, although, you planned to breast feed both of them. Otherwise, your elder son will think that mom does not love him as much as she was when his younger bro/sis arrived. OK?