Breastfeeding while pregnant

Coral • I'm a mommy to a beautiful little girl who will be 2 in October. Due with number two in February 😍
Hi guys I'm 4w6days and haven't seen my doctor yet so I have a question for you all. My 21month old does NOT want to give up the boob (she calls them buttons and they are hers, lol). Can breastfeeding in pregnancy cause a MC? My first went normal until the third trimester but I didn't go into preterm labor which I read is more of a risk if it has happened before, as in your more prone to MC or early labor of it happened before