Braxton Hicks Contractions

They've officially started. I thought I had one at around 16 or 17 weeks (don't remember) when I visited my grandfather in the ER, but I wasn't positive. Last Thursday and Friday I definitely had one on each day. It was weird, all of the sudden my lower stomach got rock solid and it stayed that way for 15-30 seconds. Then it stopped. It didn't hurt, but both times just caught me off guard!