Contractions?

This might sound dumb, but I know different women have unique experiences when they start having contractions so I was wondering if you ladies could tell me what contractions felt like for you. I'm 32 weeks tomorrow, and I've been getting more and more tightening in my stomach all day. I had a meeting for work earlier that required a long drive. My feet are super swollen from all the time in the car, and I've been having the tightening in my stomach happen off and on for about 8 hours. It's been tight more often than not though. I've read that some women have awful pain and some don't so I'm paranoid I won't know when it's happening.