How did you know labor was starting?

I'm only 34 weeks, so not planning on having baby just yet but I'm curious what contractions feel like? Is it like painful cramps? Ftm here, I haven't experienced any Braxton hicks so I'm not sure what to really look out for or expect.

Today I have been feeling nauseous for the first time in months, and am starting to get some pressure right above my pubic bone which I know is normal but it got me thinking about what'll be happening in a few weeks! How did you feel before you went into real labor?