Why do women hide a pregnancy from the father?

I recently logged into an old okcupid account I had while I was in college and I got a message from someone I went out on 1 date with. Turns out a month after we went out she found out she was pregnant with my child. <br><br>She hid the pregnancy from me, didn't tell her parents, and none of her friends knew. She didn't tell anyone until 5 months later and only because the baby was starting to show. She had our child not that long ago and no one but her best friends know the truth about the father. Everyone else believes it's the guy she's been dating who is the father. <br><br>It's been a few messages back and forth but it sounds like she was scared to tell me. That she was barely 21 and wasn't sure how I would react to finding out she was pregnant. I'm glad she decided to reach out but I'm still processing all of this. <br><br>Why do you think women would keep the paternity a secret? Or a pregnancy in general?