It is very safe to breastfeed during pregnancy - the website k e l l y m o m d o t c o m has some great information about it. I am 7 weeks pregnancy and still breastfeeding my 2 year old. Important things to consider is that your milk will likely dry up soon and will change in taste, so some children self wean during this time (I am hoping my son does as I don't really want to tandem feed). Just make sure to eat enough calories and drink plenty of fluids. Good luck.
I feel pregnant while breastfeeding. My LC said yes it can be done, my OB said no, but this was due to health reasons (I had slight bleeding and had lost too much weight). I agree I have heard that many kids self wean as the milk changes.
It can be safe, but as zazou said, it can also be unsafe depending on your health. For example, nursing lowers progesterone so if someone has low progesterone, it is probably best not to continue. I am actually doing it now. I am 16 weeks along and nursing my 18 month old. But it isn't by choice. I want him totally weaned within a couple of months. I won't tandem feed. So yes it can be done depending on the woman.
You can do it :). Totally safe. Good job mama