My uterus stretching cramps also feel a lot like this, it shouldn't last for a long time, mine might last an hour or so, if it gets too bad get checked because I went into preterm labor with my son, and that's what my contractions felt like, but they wrapped around to my stomach!
I have it constantly...its because my daughter is head down with her spine to mine :/.....but like she said it could be the bh contractions as well.
My doctor said it could either be bh or baby laying on spine I've been having it too