Ya, I can't understand that either... how can you NOT know!?
With each one of our kids, Mrs. CG knew it almost immediately.
True story: When she was pregnant with our son- she "knew" she was. So she went to the doctor and told him, he ran tests- came back negative (this is the same doctor that told her she wouldn't be able to conceive BTW... so maybe he was in denial) Anyway she went back 4 weeks later and pleaded her case again- he ran some more tests and told her he thought maybe she had a "fibroid" and would need an altrasound to confirm. So we schedule all that for a couple weeks later- She was very concerned obviously, so I went with her... It was no fibroid... it was my son! I will NEVER forget seeing his hand on the ultrasound monitor! It looked as if he was waving "HI"! She was about 14 weeks along at that point. Needless to say we got a new doctor!
For our second child- again- she "knew" it almost immediately. We were on a business trip in Vancouver and arranged to stay a few extra days to do some skiing at Whistler Resort. The day we were supposed to hit the slopes she said maybe she shouldn't. I said "shouldn't"? And she said, she thought she was pregnant. I figured she just got chicken and was using this as an excuse to bale. She went shopping and I hit the slopes with my cousin. Anyway, after we got home... she found out that she was in fact pregnant.
About 5 weeks after child # 2 was born she got the "green light" for her doctor and she jumped my bones later that day!
About a week later we were talking and she said somethings wrong. I ask what, and she says I don't know, I feel funny, like when I was pregnant with #2. I said come on... you haven't even returned to "normal" (as in aunt flo) yet. She said she knew that, and back to the doctor she went. Pregnant again! (I made an appointment with my doctor to get snipped right after that! LOL)
Women, or most certainly in Mrs. CG's case, just "KNOW"! (Maybe she's psychic!)