Can endometrosis be detected through ultrasound and is pregnency risky at the age of 37 wth thyroxine and subserosal fibroid.

No, maybe, no, maybe: Endometriosis cannot be diagnosed on ultrasound, except in the unique case where it forms an endometrioma, . Even then, endometriomas can be confused for other kinds of cysts. 37 years is not 'risky' in the usual sense, though risk of birth defects goes up a bit each year. Thyroid is not a problem if correctly medicated, subserosal fibroid it depends on "where" and "how large?".