I just found out I am pregnant. While i’m excited, I am worried because my nipples have become very dark. Is this normal? Will they stay this way?

Yes. Darkening of the nipples and surrounding skin (areola) is a very normal change in pregnancy. It is more noticable in darker skinned individuals. The color will go back to normal after delivery and will in no way interfere with breastfeeding. Congratulations!
Nipples. Discoloration without discharge or discomfort is not anything to worry about at this stage.