False labor

I am 38 weeks with my 2nd and I have been so confused by my body. During the day- I am fine. I stay at home with my 2 yr old so we are just taking it easy. As the day goes on, I progressively get worse. My lower back starts to hurt, I start having Braxton Hicks and I get nauseous. Sometimes I even throw up. It’s been happening the past few nights and I always believe that I’m in labor. Once I lay down and go to sleep, I wake up fine. It is so strange. Anyone else have gone through this?