Pre-term contractions

Heidi
With all 3 of my other kids I started having pre-term contractions that began anywhere from 18-20 weeks until delivery. I delivered my two youngest at 37 weeks exactly. 
My pre-term contractions didn't lead to pre-term labor (as I'd contract but it wouldn't cause me to dilate), but having contractions nonstop for 17 weeks was incredibly exhausting. I have a feeling they are going to start earlier with this one.
Just curious to see if anyone else experienced anything similar?