Ex girlfriend claims to be pregnant and everybody now knows.

Can you show up as positive in two or more tests and not actually be pregnant?

It is possible. Pregnancy tests can fail all the time and its quite common. Make sure she gets a test done at the doctors to confirm she is pregnant

You are more likely to get a false negative than a false positive. Get a blood test - then you'll know for sure.

You are more than likely pregnant when you get a positive result. The reason being is that the hormone hCG is produced during pregnancy. It is not the woman's body that produces this hormone, but the zygote (baby) that actually produces hCG.

If your ex actually took the home pregnancy test then, yes she is more then likely pregnant. Has she talked to you about this or is it a rumor? (I could not tell by your post.) I would go to a clinic with her for a medical diagnosis. Blood test and ultrasounds are the best way to know what is really going on.

Sounds like she pregnant...

If she has take TWO pregnancy test, both positives... it is almost certain she is pregnant.