No I don't think taking a aspirin 81mg it too late. It may be better late than never.
For chromosomes the most common is balanced tranlocations but there can be any number of rare chromosomal anomalies that have been associated with recurrent pregnancy loss.
This is from the ASRM Patient fact sheet:
"Genetic/Chromosomal Causes. A chromosome analysis performed from
the parents’ blood identifies an inherited genetic cause in less than 5% of
couples. Translocation (when part of one chromosome is attached to
another chromosome) is the most common inherited chromosome abnormality.
Although a parent who carries a translocation is frequently
normal, their embryo may receive too much or too little genetic material.
When this occurs, a miscarriage usually occurs. Couples with
translocations or other specific chromosome defects may benefit from
pre-implantation genetic diagnosis in conjunction with in vitro fertilization.
In contrast to the uncommon finding of an inherited genetic cause, many
early miscarriages are due to the random (by chance) occurrence of a
chromosomal abnormality in the embryo. In fact, 60% or more of early
miscarriages may be caused by a random chromosomal abnormality,
usually a missing or duplicated chromosome."
update: so today i took a pregnancy test that is faintly positive - however its 13 days after my IUI.. so it should be darker i think (i've had similar using same tests and my beta was 15) i called the dr and they said to go ahead and take an asprin now.. 81mg.. but isn't it too late? can it help after you've already gotten a positive test? thanks again so very much!