they shouldn't no.... it should just be like tightening and MAYBE minor cramps. uncomfortable more than anything, I suggest if they hurt you call your OB immediately
Most of the time mine feel like period cramps, and everyone's cramps are different (for example mine are never bad, but my sister's put her in so much pain that she throws up) Sometimes when I have BHs I don't feel anything though. It just depends on the individual :)
Mine were just uncomfortable, a lot like period cramps