For the first four months or so that I was back at work I was able to achieve letdown quickly and easily with an Avent Isis pump. I only work three five hour days a week, so that was working out perfectly. Lately, though, my milk will not letdown with the pump. I drink a lot of water, I think of my son, I try to relax, I do everything that I've heard of and read to get the letdown to happen, but it doesn't. I'm not sure why this is happening all of the sudden. I'm considering renting an electric pump. If anyone has tried both, does the electric pump make for an easier letdown? Any tips on getting the letdown to happen with the Isis? I'm pretty frustrated and don't have much of a freezer stash left to make up for the small amount that I'm able to pump lately. Any advice would be appreciated. Thanks.