How hard do you have to hit your stomach for a miscarriage?

Answer 1

It depends on how far along you are. if this has happened to you you have to see a doctor right away.

If this is your attempt to abort:

You could actually rupture the uterus and bleed to death that way. Not mentioning damaging your other organs without miscarrying. It is also illegal to force a miscarriage this way. Even if it is the woman's choice. She has to have it done at the doctors as the law require.