Re: Advice wanted!
Absolutely take your pump. Losing your supply after 4 days isn't so much an issue at this point (because it probably won't happen), but you will definitely get engorged and it will get painful.
And your lo will be alright. When I went on an overnight trip when my lo was 19 mos I was really concerned because she was so attached to the breast, especially at night. It turned out to be much easier for DH to get her back to sleep without me there because she knew there was no breast to be had. I'd left a few bottles just in case he needed to give her some at night to get back to sleep and he ended up not even needing them.
“We are not put on earth for ourselves, but are placed here for each other. If you are there always for others, then in time of need, someone will be there for you.”