painful Braxton hicks

Nessa
I'll be 19 weeks on Thursday and I've been feeling BH since around 13-14 weeks. I spoke to my Doc he just said as long as I don't have more than 4 in an hour It's ok. This is my third baby and I truly don't remember them this early with my last (now 6 years old) My BH aren't extremely painful and don't last long but a few seconds about 5-6 seconds maybe. But they do hurt enough that I have to take that  one I breathe. I get a few a day just not 4 in an hour. I'm wondering ir anyone has been though It. I'm scared of preterm labor in the long run