Early Labor

I’m currently pregnant with number two. When my daughter was born 2.5 years ago I went into labor 6 weeks early. My water broke unexpectedly. There was really no other issues or concerns throughout my pregnancy. Also my whole labor and delivery was only 10 hours long. I was surprised because I’m young, was 23 then, 26 now and had no symptoms or issues throughout my pregnancy so having an early labor and short delivery was weird to me. This time around I’m supposed to get shots starting at week 14-16 and continuing once a week until I give birth. This is supposed to help prevent early labor.

I’m wondering if anyone else has experienced this and if they still went into early labor with their other child(ren). Or what your experiences were. Just a little worried is all.