Had a baby with her pants on! Ouch!!
Again, sadly, I know someone who didn't find out she was pregnant until she was 6 months pregnant. My best friend! She had lost a ton of weight and had this great boyfriend she didn't think was so great. Big dummy! They broke up and she put some weight on. Thought nothing of it. She was a big, big girl anyway.
She started feeling 'off' and got herself in an anxiety attack and went to the hospital where they ran a bunch of tests on her and gave her an ultrasound. It was then they found she was pregnant - 6 months gone already! She was so embarrassed and felt like such an fool. She never bonded with that boy and the father that she'd broken up with didn't even believe her until the baby was born.
It can happen, I just think with weird periods and strange weight fluctuations, you can attribute all the pregnancy symptoms to something else, you know?