I didn't get any bh's with my other PG's either. What you're describing is what I've had but now mine are getting much stronger.
I can feel them coming on and in a way it reminds me of the let down reflex. I had those really strong all through breast feeding both the boys. I know not everyone feels a let down with b/f so you may not have had that one either.

As well as the tightening, I get a hot flush and lose my breath a bit. By the end of the day or if I'm feeling really tired I have a bit of pain with the bh which extends down my groin and thighs too.