What do contractions actually feel like?

FTM— have lots of BH tightness for weeks now and today I had this cramping just on the whole right side of my stomach that was pretty intense for a min. It went away but it had me thinking what do they actually feel like? Will it be different than cramps or gas cramps? Or will the only way I’ll be able to distinguish them is how frequent they become? Just curious! Almost 34 weeks and getting eager over here!