Kids wandering a store = trouble.

I have a problem, and I don't know what to do about it.

I've never had to do it before.

So here it is.

My husband is working 13 days straight right now, with the 14th day off. 10-12 hour days.

My sister was staying with us for a couple months, but has now moved out.

So my problem is, how am I going to go grocery shopping ALONE with three children, three and under. They can't exactly walk. I mean of course they all can walk, but Bubu is the only one that would listen for the most part. He is so slow though that I would be in the store for a couple hours instead of the hour it already takes me, and talk about stressful! They have the carts that fit two children, but not three. If I put Bubu in the basket of the two kid cart, by the time I start throwing groceries in, there won't be any room for him. I have to go shopping every weekend, and it's the kind of shopping where the cart if full to overflowing. I already make it as simple as possible. I always go to the same grocery store so I know were everything is, I make detailed and categorized lists that for the most part follow the lay out of the store so that I minimize backtracking. But it's still a procedure. Normally I either leave the boys at home with the hubby or we go to the store together and use two carts. While hubby's been working so much my sister has been helping so I hadn't been faced with this problem yet. I'm not really worried about the kids freaking out, they usually do really well when they go with, except for the occasional fit from Atty. But he's a redhead so go figure. It's just containing them that is the problem, because anyone with kids knows that kids wandering a store = trouble. I use to put one in the backpack and the other two in the cart, but they are all so heavy now. I seriously don't know what to do. It seems like a little problem, but I can't get around the weekly grocery shopping, or make it go any quicker, so I am going to have to face this next weekend. The only other thing I can think of is to wait until my hubby gets home, late at night and leave him with the kids and go then. That might be the only solution, but my hubby is so burnt out by then that I hate to do that to him. Plus quite honestly I am pretty burnt out by then too and the last thing I want to do is go grocery shopping late at night, uggg....

Does anyone else have any solutions? What do you do? What do you think would work best for me? What am I going to do when I have four kids, four and under! Good Grief.