What do contractions feel like?

Baby Girl is at least 64 days pregnant. She has been moving around alot today. I was resting my hand on the side of her belly and right behind her ribs will get really hard for about 30 seconds, then go back to being kind of soft. It almost feels as if a kitten is really pushing out but there's no rolling movement normally felt with it, it just gets hard and then relaxes, and it's more in an up/down line rather side/side line. It happens around 5 minutes apart (guessing because I haven't timed it).

It sounds liek contractions- the best way I can describe it if like her stomach is squeezing together for a few seconds, then relaxing.

I didn't even know mama kitty was having contractions until she went into full on labor, but looking back I remember her sides clenching (I thought it was from the scratches I was giving her) and her fur kind of moving up and down.

The whole belly clenching didn't come for a few hours. But she had a gray tabby and a black kitten. It was long and hard. She had a really hard time with the first one (they both came butt first). I was actually fixing to take her to the vet, thinking it was too big for her, when he finally popped out.