I breastfed DS for over 2 years and never felt a letdown once. DD is just over 3 weeks old and for the last few days I've noticed occasionally my nipples have tingled momentarily between feeds. They did it again just now and when I checked the milk was pouring out! I don't notice it when I feed her though, but I'm sure it must be letdown. Has anyone else had different sensations with different DC?