breastfeeding issue

Jane
Baby is on week 4. My nipples finally don't hurt n burn as much anymore. But I've notice that after every feeding my nipples are white. But baby n I don't have thrush.. his tongue is white after a feeding but goes away. When he feeds on one the other has a let down. My baby bottom also has a rash. Could I have thrush or yest infection? He had enough poops (yellow n orange running n seedy) n pee diapers. But I feel like maybe I do?? I have a dr appointment Thursday so I'll ask then. But meantime curious. My nips do burn every now n then but it's not as bad anymore