My DD (8 weeks tomorrow) has never really got the hang of latching so I am expressing breast milk for her. I don’t quite manage to exclusively feed her on expressed milk so she generally has a couple of formula feeds too.
I usually express at around 2am around 5 am and then around 730/8am. Last night my toddler was sick and came in bed with me, I didn’t want to wake him so I left expressing. Woke up drenched in milk 
Do I need to be expressing regularly overnight? And when will the milk leaking stop - it’s a pain and often happens when DD is in the sling so we both get a bit sticky.