Sounds like your body having a practice! I didn't have anything like that last time though until it was the real thing. But as we've said before, now we know what it feels like we know what to look for.
I'm feeling a bit yucky today. Was just standing in the queue in the shop and I felt a bit dizzy and sick. Good job we don't have too much to do today, just ballet which is a short walk down the road. Also had tingly hands and feet last night but looking online that seems to be fairly common.