Mine started around 20 weeks and my LO came at 37 weeks. BH aren't a sign of preterm birth. No worries! :)

Braxton hicks are very normal. I started having them at 22 weeks. It's just your uterus practicing 

If your worried have doctor monitor you for a little bit.I had the same problem around those weeks and it turns out it was a irritated uterus because I had an uti which I had no symptoms.they gave me antibiotics and it stopped but I'll occasionally have it now and then but I drink water and it helps bc being dehydrated can cause cramps.so make sure you drink plenty of water.

This is my second successful pregnancy so far and I started feeling them around 14 weeks. I think I got them in my 20s with my first but I had NO idea what they were lol.

I'm 32 weeks and iv been having them for a few weeks now. At first I thought it was food poisoning lol but now I know it's just Braxton hicks 

I've been having them since about 18 weeks