6 Braxton hicks in 20 mins yesterday

At my appointment yesterday they decided to do a NST. My son has a single umbilical artery and they don't like that I've been having a lot of BH. The baby's heart was great, but I had 6 contractions in 20 mins 😮 They were concerned I was going into preterm labor and sent off for a fetal fibronectin test. Luckily, it came back negative! I'm suppose to take it easy and call if they become painful or uncomfortable enough to wake me out of my sleep. Keeping fingers crossed for 10 more weeks!!