Article here. Excerpt:
"Your goal is to avoid becoming a victim of "Paternity Fraud." This is when a mother lies about who a child's father is for the purposes of monetary gain. In your case, you could be on the hook for 18 or more years of child support for a child or children who aren't yours.
The bad news is that paternity fraud is not uncommon. The American Association of Blood Banks found that 30 percent of the men in paternity tests are ruled out as the biological father (other studies put that number at 25 percent).
...
Unfortunately, even challenging paternity within the window doesn't guarantee that you'll avoid being defrauded. In many states, when a child is born during a marriage, the husband is presumed to be the father - biology is irrelevant. So even if DNA shows that he's not the father, he'll still owe child support."
