I had a frozen embryo transfer yesterday! can the embryo die straight after being put into the womb? especially if you get up to quick?

Relax: Congrats on your et. There's no reason healthy embryo(s) would die right away, and 'getting up too quickly' isn't even on the list. Good luck!

Pain after FET: Some patients will experience sharp or stabbing pains, on the other hand, that may not be from implantation but more from the ovaries. About three days after the retrieval, the ovaries will refill with fluid and this stretching of the follicles and ovaries certainly can cause “pain” in one side or both sides.