Pumping help!

My boyfriend and I are planning on attending a concert in May, it has a four band line up with basically two headliners so it’s probably gonna be a fairly long concert. It literally just clicked I have no idea what I’m gonna do with pumping. Please help. Obviously I’ll have to pump prior to. I can’t leave the venue once I’m there. And I can’t bring in a bag big enough for my pump so I am lost. Please help a girl out 😩