Previous Preterm Birth

My first baby came at 32w2d for an unknown reason (12 years ago). My pregnancy had progressed pretty easily, although my fundal height measurement was behind for 2 appointments before I went into labor. I am really short and petite though, so may be unrelated. After the birth, they tested for infection and anything else they thought may have caused the preterm labor but I got 0 answers. I'm really nervous about having another preterm labor and NICU stay. I'm on vaginal progesterone until 36w. Has anyone had success making it to term after a preterm labor?