The policy wasn't as simple as the English name for it. It encompassed many other rules including the ages men and women could marry and the ages they could have kids.

For certain people (mostly ethnic minorities) there was a higher limit. In rural areas, the limit was usually more relaxed than urban areas.

Many women who got pregnant before they were allowed had to have abortions. Some women were forced to have IUDs, and some women were sterilized.

So, depending on who you were, where you were, and how old you were, the one child policy might have restricted you to one child, or it didn't.