Ooh yes, quite a few of us mummies did this! I tandem nursed my second while pregnant with my third, and honestly it's okay, just make sure you're eating enough and drinking lots of water because your body needs extra nutrition for both. Some people worry about contractions from nursing, but best to check with your doctor first, especially if you've had complications before, since everyone's situation is different. A few of my mum friends said the nipple sensitivity during pregnancy was quite intense though, so don't be surprised if it feels different! All the best with your pregnancy and nursing journey.