Anxious feeling before labor?

St

This is my 3rd pregnancy and I'm 34 weeks along. The last 2 days out of nowhere my body has just been feeling antsy, almost like an anxiety attack is coming but nothing. My heart feels like it's beating a little faster than usual...Nothing is bringing it on, I'm not nervous about anything. I'm wondering if this is an early labor sign? Has anyone had this feeling and gone into labor shortly after?