When would an embryo first be exposed/affected by what the mother injests? when would i need to stop a med so the embryo is not exposed?

Depends : Every medication is different as to how long it takes the body to flush out of your system. Check with your prescribing doctor when it would be safest after stopping a medication to try to conceive.

Organs start forming: 3 weeks after conception, so checking with your OB ; your treating physician prior to conception is best ( of course, since it was advised by a fetal-maternal medicine specialist). Edwards syndrome is from a genetic accident during cell division. You did nothing prior to or during pregnancy to cause it. Fragmin (dalteparin) is a class b drug in pregnancy, meaning it has no known adverse effect on a fetus.