I'm 33 weeks exactly and ended up in the hospital yesterday with contractions every 2-4 mins. Turns out it was due to dehydration. I had drank 2 bottles of water before they started around 2pm (not nearly enough). It was 70 degrees and I wasn't feeling thirsty so never thought anything of it. I also wasn't doing anything strenuous, they started while I was walking around a mall.