Contractions...

Can someone explain how to tell if you’re having contractions vs Braxton Hicks early on? I’m 35 weeks and I have been up every night for a couple weeks now about every hour for pain or to pee, but last night I had some seriously bad pains and I think they may have been Braxton Hicks or something,but am unsure and so many people say “you’ll know if they’re contractions”... at my doctor appointment today she asked if I was having any contractions at all yet because it would be normal and I guess I should have asked then! Mostly feels like baby is smashing organs in a specific area where I had the pain last night..