This has been shown to be wrong. Basically the only thing abstinence only education does is delay by a year or two, the age at which people first have sex.
Then they proceed to have higher rates of every negative outcome.
So what you are saying is that people have sex later, thereby there is less sex having, which is exactly what the abstinence teachers want.
Then you say higher rates of negative outcome, without mentioning whether you consider rate of sex having to be a negative outcome.
(I don't disagree with the assessment, it follows the exact logic I posited. I'm not sure why you're taking my comment as being in support of abstinence - it clearly isn't)
Then they proceed to have higher rates of every negative outcome.