I have seen people asking me this question often, but it's easy to find, yet not exactly available directly.
Go to your Facebook Friend Requests page, there you'll find the Friend Suggestions and Friend Requests by default. Below that, you'll find a link "View Sent Requests", click on that, in this section you'll find all the friend requests you gave, and yes, which are in pending state.
We might have given plenty of friend requests to the people we know and to the people we want to know, but we don't really check later whether our friend requests got approved or not. This page will help you to finalize whether you need to cancel your pending requests or not. :')