At 6 weeks. Edith had a bit of oral thrush. She didn’t seem in pain with it but it infected my nipples. We both had a cream to apply and eventually it cleared by itself. The thrush made my nipples sore and red. It wasn’t too bad but it did make feeding uncomfortable for a while.
I have been pretty luckily and have so far *touch wood* escaped mastitis, I have however have had quite a few plugged ducts. I’ve managed to clear them myself, with using various techniques. Applying hot flannels in the bath and massaging the duct when feeding. Also feed from the affected boob first helps but make sure you still feed from both so you don’t cause any plugged ducts to that boob either.