This is probably a stupid question but does your milk supply just adpt when baby starts sleeping longer / thru the night? My LO is 15weeks and this week has just started sleeping from his 10.30pm feed til 7.30/8am ( halleuia/handstands and cartwheels ). I obviously don't want my milk supply to dry up but there seems plenty in the morning and I feed on demand during the day. Will it just adapt to less feeds or do I need to express a bit? Thanks in advance.
Nope, no need to express (especially not in the middle of the night - make the most of the sleep!), it will just adapt to what she's taking. You may well feel quite engorged for a couple of nights until your body get used to the missing feed but soon you'll just be nice and full in the morning.
The supply and demand system is so good that even if she (God forbid) occasionally wakes in the night you'll still be able to feed her and feed again as usual in the morning.
Yes it does adapt, though I always used to get mastitis when my little ones skipped more than one feed, rather than adapting gradually. (It is easily treated with neurofen and lots of feeding from the affected side if caught early, so doesn't have to be a big deal - just be aware if you start to get a burning pain and feel ghastly that you need to get back onto MN to catch it early!)