The Rebbe advises seeking medical consultation, strengthening Torah, mitzvot, family purity, and tzedakah, checking tefillin and mezuzot, and giving charity before candle lighting. If she is a Bat Kohen and her husband is not, he should study a Talmudic tractate. The Rebbe blesses them for good news.
https://www.torahrecordings.com/rebbe/igroskodesh/014/005/5157