What do contractions feel like?

Ashleigh
Ftm and wondering what I should be looking for when it comes to contractions. I've googled it and there seems to be so many different answers. 
I went to a rock concert last night (35weeks pregnant) because we got the tickets as a Christmas gift and not long after it started, I started feeling some pain in my lower stomach. Not really bad pain, just uncomfortable. It wouldn't come and go and once we were home it stopped. I'm wondering if it was some contractions or what contractions feel like if not