Is our marriage invalid because we do not remember repenting from zina before the marriage contract, and because I do not remember menstruating before the marriage, even though no pregnancy occurred?

An adulterer is not permitted to marry an adulteress except after repentance, based on the Almighty's saying: (The fornicator does not marry except a fornicatress or a polytheist, and none marries a fornicatress except a fornicator or a polytheist, and that has been forbidden to the believers). If the repentance occurred before the marriage, then the marriage is valid. However, if it occurred after the marriage, scholars have differed. The majority of jurists hold that the marriage of an adulterer and an adulteress is valid even if they have not repented. The Hanbalis, however, are of the opinion that the marriage of an adulteress is not valid until she repents. According to this view, it is safer to renew the marriage contract if she had not repented before the contract.

Repentance is achieved by regretting the sin and resolving not to return to it. As for istibra' (ensuring no pregnancy) or iddah (waiting period), these are not obligatory according to the Hanafis and Shafi'is. It is safer to renew the contract if possible without informing the wali (guardian) of the true nature of the matter. If renewing it is not possible except by informing him, then that is not obligatory, and the marriage is considered valid based on the opinion of the majority of scholars.