I’ve had this a few times. It’s been called a few things; prodromal labour, false labour and uterine irritability seem to come up most often.
I get into a contraction cycle which can last hours, even days… then it just stops.
in my first pregnancy this happened at 35 weeks and I was admitted because it lasted for 4 days, it did then actually turn into ‘real’ labour and I had my son at the start of week 36.
this pregnancy though it’s been all over the place. I’ve been admitted 4 times, starting in week 32. Each time my cervix has been closed and I’ve eventually been discharged once the contractions stop.
they’re different to braxton hicks in that they are regular (falling into an obvious pattern that can be monitored on a CTG) and they are often uncomfortable rather than just tight. Particularly the later episodes in weeks 34-36 where it felt like I had period cramps with the tightenings.
it’s enormously frustrating, and my first pregnancy taught me that it’s better to be safe than sorry because whilst I had several days of nothing really happening, when active labour started it was quick. I went from 1-10cm in less than an hour and baby was here within 2.
I’ve done some reading which suggests that uterine irritability can become worse with subsequent pregnancies.
best of luck with the rest of it. There’s not a huge amount of information available when it comes to this stuff and I’ve definitely had more than a few moments of resenting not having a ‘normal’ labour experience.