Regular BH for over an hour, then no more contractions but sharp pain???

Has anyone had this happen???

I woke up last night because I was having a really painful BH at 3:15. Went to the bathroom, drank water, got back in bed and continued to have strong BH for over an hour. (I've been having BH contractions since 16 weeks and often - this is not the first time I've had several in the course of an hour, but these ones were more painful than the others... still, not as painful as real labor). I started timing them at one point and I had about 11 in the course of an hour about 5-7 min apart. I kept changing positions in bed and it didn't help. Finally, I decided to get up and get ready for work at 4:45 when I realized I wasn't going to be able to sleep anymore. I still had contractions (although I stopped timing) until around 7:30. I got to work at 8. By then, the BH went away and were replaced by a sharp shooting pain in my low belly when i walk. It's been coming and going all day, but other than a few contractions everything seems normal again. Baby is moving great.

 What the heck is going on? This is my second, and I'm used to BH, but it really confused me how there could be so many and then they just stop... and now this other feeling?

 Anyone have ideas?