I'm 17 weeks 4 days pregnant with twins. Yesterday I wanted to scrub the floor, and noticed that after just a few minutes of being on my hands and knees I got really bad abdominal pain. I stopped immediately, rested, it went away. Today I decided to try again and exact same thing happened. I've read that being on all four is supposed to be helpful for belly pain, and in my case it seems to have the opposite effect. I guess it's just ligaments stretching, but I wonder if that is something others experience too. Can't wait for my next appointment to ask all the questions about all the new aches and pains that started in the last 2 weeks!