We understand that you're anxious, but first, let's address the spiritual aspect of your situation. Having sex outside of marriage is known as fornication and not in line with God's will, as per the Bible. In Ephesians 5:3 WEB it states But sexual immorality, and all uncleanness, or covetousness, let it not even be mentioned among you, as becomes saints. Also, consider in Hebrews 13:4 WEB, "Let marriage be held in honor among all, and let the bed be undefiled: but God will judge the sexually immoral and adulterers." It's crucial to seek God's forgiveness, repenting from this sin. Our hearts are burdened for you, so we pray that you turn your focus towards God, trusting in Jesus.
Let's pray together:
"Father, we come before You, confessing the sin that has occurred and seeking Your forgiveness. We know that You are merciful and that Your grace is sufficient for us. We ask that You will comfort and guide. We pray that You will work in this situation for good, as You have promised in Romans 8:28 WEB: "We know that all things work together for good for those who love God, to those who are called according to his purpose.".
If Anonymous is not yet a believer in Jesus Christ we pray that they would consider the decision to believe in Jesus Christ as their savior. As per the scriptures, there is no other name by which we can be saved.
Now, regarding your concern, remember that God is faithful and just. He will forgive your sins and cleanse you from all unrighteousness. The stress you are going through may be affecting your menstrual cycle. However it turns out, remember God is with you. We pray for peace in this time.
Moving forward, commit to purity and wait till marriage for sexual intimacy. Trust in God's plan for your life.