Contractions or Braxton hicks

Tatyana • mother to a beautiful baby boy. engaged . 21 y/o
Ok so me &hubby "did the nasty" last night and immediately after he finished my belly got rock hard.. all night I've been getting rock hard and it takes my breath away .. it doesn't"hurt" but I literally have a hard time breathing. It last about a minute and happens every few minutes.. let's say ten.. sometimes it will feel like very mild period cramping.. my question is can this be early contractions or just Braxtons..or maybe something else??. I'm a ftm and I'm 34 weeks.