Committed Fornication but Both Repented after Her Monthly Period and Want to Marry
15-3-2023 | IslamWeb
Question:
Assalam walikum, I know of a couple who fornicated with each other. Few weeks later the girl got her menses. Both of them repented after her monthly period was over. Do they need to wait for her next period in order to get married to each other? Even though they were not involved in sexual relation after they fornicated but they didn't repented until her period was over. Please consult this question with a scholar since the answers I have already got are different
Answer:
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad 
is His slave and Messenger.
Scholars have stated that two conditions are required for marrying an adulteress or one who committed fornication: Repentance and ascertaining that she is not pregnant. So, if what happened is what’s mentioned, that this man and this girl have repented, and the girl has menstruated, then the two conditions have been fulfilled. Thererfore, there is nothing wrong with them getting married. The fact that repentance has occurred after menstruation does not harm.
We point out that the obligation of the one who has fallen into disobedience is to conceal himself and not tell anyone about it.
Abu Hurayrah 
narrated that the Prophet said: “All my nation are forgiven (for their sins) except those who commit sins openly (or disclose their sins to people). An example of such disclosure is that a person commits a sin at night, and though Allah screened it from people, he comes in the morning, and says, ‘O so-and-so, I did such-and-such (evil) deed last night.’ Though he spent his night screened by his Lord (none knowing about his sin), yet in the morning he removes the screen of Allah from himself!” [Al-Bukhari and Muslim]
Allah knows best.