I Think My Cat Has Given Birth To Her First Litter, But She Acts Like She's Lost Them. She's Been Acting Like This For A Couple Of Days Now, And Looks Really Upset. What To Do?

I need to know if my cat has given birth and if so, where. This is her first time, so i don't know what to expect. I also found something like her cord on the kitchen floor? She wonders around like she's looking for them. Im really scared that they might die if not found soon. Please help? X