Interesting topic, but I'll share.
My ex (1/2 German, 1/2 Italian with an awesome pair of legs) attempted to pull the ultimate trap on me. We broke up but were good friends for a while. Then one day many months later, we got a little frisky and we had sex 1 time. 10 days later, I get a call telling me that she's pregnant

WTF! What made you check and how do you know? She said because we didn't use protection and she just had a feeling.
FYI, the sex that night was kinda whacked. I will swear that I didn't even bust a nut. But whatever, stranger things have happened. Still, I couldn't get over that she got a pregnancy test 10 days later.
Meanwhile, I'm already in a relationship
I knew there was not going to be much that I was going to do for my ex, so since I was buddy buddy with her mom, I called her up and told her. Out of anger, my ex then called my parents and told them. So everybody knew
My ex was pulling all the stops, saying she's not going to get rid of the baby, that she wants me to be with her, that we need to get prepared for the baby etc etc etc.
I'm 21 years old and there's no fucking way that I'm ready to be a dad. Suprisingly enough, my biggest ally was her mom. My Step-dad and mom on the other hand took my ex's side and told me to be with her no matter what, or risk alienation completely.
A few months pass and she tells me that she goes to a Planned Parenthood clinic to find out the due date etc. So I call the place because I wanted to know when the baby is due. The receptionist tells me that _____ ________ was never there that day.
wtf, wait a sec.
"No sir, she was never here. We aren't even supposed to tell you this information over the phone anyway."
WTF
I confronted her, she said she was there. I didn't believe her. And we decided to stop speaking to each other. A few months later, I call her mom for an update. Her mom says that her daughter had a
miscarriage.
Sure she did
Since then, I've been the most paranoid motherfucker around. I don't trust many women. Oh well, live and learn.