All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
Saying that you have lost your virginity illicitly with your fiancé could mean that it happened before or after finalizing the marriage contract and it could have happened through sexual intercourse or with his finger. If you had not yet concluded a marriage contract and you lost your virginity with him by sexual intercourse or by his finger, you have committed an awful sin that requires your sincere repentance. Indeed, whoever sincerely repents to Allaah The Exalted will be forgiven. In this case, he will not be obliged to pay you a dowry as long as you were not forced to commit fornication with him.
On the other hand, if you had already finalized the marriage contract then you lost your virginity with him by sexual intercourse or by his finger, and then he denied it claiming that you were not a virgin when he married you; since he did not see blood, then his claim is groundless and is rejected, even if he had stipulated that you should be virgin as a condition in the marriage contract, because the discharge of blood is not a fundamental sign of virginity. Furthermore, seeing a piece of the hymen is stronger evidence that proves your virginity.
Moreover, even if we assume that the hymen was broken before that because of some strenuous activity, a wound, or the like, and he stipulates your virginity as a condition in the marriage contract, he does not have the choice to annul the marriage; since losing virginity this way may be unknown to the girl’s Wali (guardian) and to the girl herself.
A husband does not have the choice to annul the marriage unless the wife had lost her virginity by previous intercourse. Moreover, if he specifies her virginity as a condition in the marriage contract, and he claims that he has found that you are non-virgin, while you claim that you lost your virginity to him, then the final say is to you based on your oath. However, if he did not stipulate your virginity as a condition in the marriage contract, he has no choice to annul the marriage and you do not have to take an oath.
Allaah Knows best.