I am having the same questions, so I'm happy to have found this thread. I had strong BH with my first pregnancy starting the 2nd trimester and lasting forever! I was evaluated for PTL at 24 and 32 weeks but it was only BH. For my second pregnancy, I miscarried at 7 weeks while nursing my son heavily, that is frequently throughout the day and night and never knew if it was related. Now with my 3rd pregnancy, I am nursing my DS 2x a day (sometimes more), and have started to feel BH starting at 17/18 weeks (I am 19 weeks). I had an orgasm in the 18th week and had strong BH for 2 days which scared me!! Since then I am feeling them often throught the day. They are worse when I don't get to rest during the day (so I am trying to get my feet up at some point), and I feel them when nursing. I DON'T WANT to have to stop nursing, and will be distressed if I'm advised by my MW to do so. If this pregnancy will be like my first, I have a long road ahead of me with BH that will and will not be r/t breastfeeding.