Am I in Labor?

This seems to be a question I'm asking myself pretty often lately. And last night, I was confident it was happening. I was having pretty strong contractions about every 3 minutes that lasted about 30 seconds. This went on for about an hour and a half. I wasn't 100% confident though because I haven't lost my mucus plug nor had any leaking or bleeding. So after the hour and a half, I decided to call the hospital to see if these things needed to have happened in order for me to truly be in labor. The nurse said no. So I hung up thinking ok. . .maybe this is the real thing. And to my dismay, I didn't have another contraction after hanging up the phone with the nurse. So, I'm back to patiently waiting for the baby to make her appearance. I keep telling her I'm ready when she's ready.