Does the wife have the right to demand her legal rights, the deferred dowry, and the contents of the marital home, and would she be sinning or wronging her husband, if she discovers after marriage and after an incomplete pregnancy a previous health problem (menstrual disorder) from which she had recovered before marriage and forgotten about it, while the doctor confirms her ability to conceive but with treatment?

If the situation is as you described, and there was no deceit or injustice on your part towards your husband, then there is no sin upon you, and he has no right to annul the marriage for the reason mentioned. If your husband divorces you, then you are entitled to all the rights of a divorced woman, as clarified in Fatwa no. 40248. Furthermore, he must fulfill your right to the entire dowry (sadaq), including the deferred portion, and the household furnishings if they were part of the dowry, once the deferred period is due, whether he divorces you or not.