What do contractions feel like to you?

J
Every time I have an appointment woth my midwife she asks if I have any contractions...I always say no, because I don't even know what they would feel like? 
Sometimes a get almost like a tight cramp-like feeling? Could that be it? Or would I know?? Even with Braxton hicks, I have no clue!!
Btw in 34 weeks if that helps lol?