What is the difference between the Non-Invasive prenatal paternity test and other prenatal paternity tests?

How early can I take the non-invasive prenatal paternity test once I found my pregnancy?

How is the DNA sample collected?

What if the parties to be tested in different citys?

How long does the paternity testing while pregnant take?

Which kind of discreet sample will be acceptable for the paternity while pregnant?

Can I learn the gender of my baby through the prenatal paternity test?