Funny enough I had no idea what BH felt like as never had them with my other 2. I've had these funny feelings for quite some time now (I'm 34+1) which felt like baby getting in a funny position which kind of took my breath away for a moment and gave me a tightening feeling in my head but I never knew these were actually BH until last night, just thought it was a funny move from the baby. The reason I now know if that I had to go in for a trace last night to check movements as he'd been very quiet, and whilst I was being traced, they asked if I could feel the tightenings which I confirmed I could in my head and then yes, in my tummy too (which I think I felt more due to pressure of the belt on me). I was having them every few minutes and now I realise that I've had this for ages, just not as frequent as I've had since last night. The tightening in head thing they found odd but eventually they let me go (and a quick google shows it's quite a common thing for people having BH). They didn't tell me at the hospital they were BH as they weren't sure if it was that or early labour. But as this is 24 hours later and just the same, I'm putting them down as BH.
So I'd say yes, if you're tighening then that's probably what you're having too.
Roxy - I'm the same as you - I kept getting these weird tightnings when I was walking and I thought it was the baby moving, but in the last week they've got much stronger and more distinct and I'm pretty sure they are BH - I can feel how much harder my stomach gets, and they usually pass within a minute. They don't hurt, but they're bloody uncomfortable and they take my breath away a bit sometimes! Am 28+4.