I've had them almost constantly for the last 3 days. They dont just tighten my bump but they make me have a surge of blood to my head and my face and ears go all hot. Plus my chest gets really tight, like when you've been running really hard and its almost painful to breathe. I have to really fight to catch my breath, especially when I'm laid down. I wouldn't mind if they were actually doing anything but his head is still 4/5 palpable and I've had no labour signs whatsoever.