Hello, I have gone through your query and understood the concern. The declining hormone level is suggestive of a missed pregnancy. The cause of this happening can be known only after examination of the aborted products of conception histopathologically, genetically and chemically. Most common causes of an abortion in the early weeks are genetic defects, hormone deficiencies, blighted ovum and so on. The position of the uterus can sometimes be a factor, retroverted uterus carrying a higher risk of abortion. To know if you have aborted, you should confirm through a sonogram. it is not possible to abort spontaneously without pain or bleeding. Hope this helps.