Dont worry - It is enitrely possible to manage 3 -
I admit, back when I only had 2- I was really worried about having less hands than children BUT I have learned that

- a stoller solves that problem
-kids learn from each other (and this works predominantly for Good rather than evil!)
-usually kids stick together and play together and are unlikely to run in 3 different directions as they will compete for your attention and as such want to stay in your sight so you can see they are being wonderful
-there is this wonderful innate invention called 'perfect angel syndrome' where if one child is getting in trouble or being told off - the others become perfect little angels (Temporarily)
-the eldest usually becomes a leader (hence the birth order theory) and loves to tell the younger ones what they should and shouldnt be doing!
- children are naturally 'dobbers' so if there are any problems you will have lots of warning
- Childrens loyalty is usually to the parent rather than the siblings (hence sibling rivalry) - well at least until the teenage years I am told (arent there yet)

HAVING SAID THAT
- never show fear (children can smell it)
- never forget the pusher when you go to the shop
- always stick them in a trolley if you do forget the pusher
- avoid shopping with them all at once if at all possible
- ear plugs are a marvellous invention, I'm sure they were first invented by mothers who were inspired to invent them whilst on long car trips

Mumeee (mum to soon to be 8 - 12,11,6,5,3,3,2,due Aug)