Most people at this stage would pass everything on their own. But if it is failing to pass then yes.
Yes, you could, but you probably wouldn't know that it was a miscarriage
Vinegar will not harm a pregnancy.
Miscarriage
If you have a miscarriage before week 22 there's not much they can do.
Can not find anything that would indicate that they can cause a miscarriage. The safest ones to use during pregnancy is Loratadine or Chlorphenamine. If you can not take those your doctor might give you Cetirizine. Seems like you had a miscarriage because the zygote was not viable. Happens in about a third of all pregnancies.
You have to see a doctor and have a surgical abortion.
Not necessarily. The hormones that make a pregnancy test read positive stay in your body for a little while after a miscarriage.
If you mean that shouting at the fetus or around the fetus or belly during the pregnancy can hurt it, the answer is no. And they can't hear until around week 20.
I believe the it is most common for a miscarriage to occur between the 6th and 13th weeks of pregnancy.
A miscarriage can happen at anytime from implantation of the fertilized egg up until the 20th week, but most of them occur in the first 8 weeks. After the 20th week, it is called a stillborn birth instead of a miscarriage. A loss of pregnancy during the third trimester (after 28 weeks) is usually called a premature stillbirth and not a miscarriage.
You can have a miscarriage at any time but rarely sex is the reason unless you have a very sensitive pregnancy and the doctor have told you to not have sex.
Possibly, if the pregnancy ended very early the hCG may have returned to pre-pregnancy levels before the miscarriage. It is more likely for the test to be negative a few days to a week after an early first trimester miscarriage.