Swistle is asking how'd you find out (that you were pregnant)? How fun! Lets see...
My husband and I planned on having kids. In fact we had been talking about it a lot! We were doing some long term planning trying to decide when to start trying to get pregnant. We had decided to start tying in about September of 2006. Well, on a Sunday early in June we went 4-wheeling with a friend. It was fun and something I had never done before. While we were out bouncing around I noticed that my chest was very sensitive. I thought about it all day. When we got home I asked Jared to come and chat with me on the bed. I was so nervous. I knew we both wanted this, but were we ready? I said, "what would you say if I told you we were pregnant?" He looked at me and was not sure what to say. I told him that I was a bit late (not much), but that and a funny feeling was about all I had. He said we should go out and get a pregnancy test. we came home with it and he was excited for me to take it, but I was too nervous. I told him I'd do it after dinner, but just before we sat down I knew I couldn't wait. It was a faint positive, but positive. I called the doctor the next morning and got them to schedule a blood test for the following day (Tuesday). That test too came back positive. Then we started getting really excited.
The following Sunday was to be Father's Day. I told Jared that we should send a card to each of our fathers saying Happy Father's Day Grandpa and see who called first. He was not too excited about that idea. We did decide to wait to tell the parents until Sunday. We called his parents but his mom was out. His dad was suspicious of why we wanted to talk to both of them at the same time and guessed. They were very excited though. It went much better when we told my parents. I got both of them on the phone and I said Happy Father's Day, and Jared added Grandpa. My dad was so excited. We managed to wait to tell anyone else until the end of the first trimester.
I don't know how common it is, but my sister said that she knew because her chest was sensitive too.