What should we do if my fiance missed her period after unprotected intercourse 12 days ago?

The birth control pill is best if taken within three days of having unprotected sexual intercourse. The mechanism of action is to prevent the ovary from releasing an egg. Be mindful, though, the morning-after pill is not 100% effective. To be safe, you should look out for the signs like missed periods, nausea, or breast tenderness. If you get any of these symptoms, it's best to do a pregnancy test.

Late periods and vaginal dryness can have many causes of which stress, hormonal imbalances, and infections are included. Kindly seek medical help if you experience any uneasiness or unusual symptoms.
 

Late pe­riods can feel worrying; they could me­an pregnancy. You might feel nause­ous, exhausted, or nee­d the bathroom frequently. Howe­ver, stress, routine change­s also delay periods. Take a pre­gnancy test if you've missed; waiting a fe­w days gives accurate results. 

Emergency contraception is intended for occasional and emergency use, not as a regular form of birth control. While there is no strict limit on how many times emergency contraception can be used, it's important to understand that it is not as effective or reliable as regular contraception methods.

Repeated use of emergency pills can disrupt hormonal balance in your body and cause irregularities in your menstrual cycle. It's recommended to speak personally with a gynec about more reliable and appropriate forms of contraception that can better suit your needs and provide ongoing protection.

The pain can be because of harmonal change, muscle strain or injury. Get it checked early to avoid any further problems.

The  treatment depends on the cause of the urine leakage. I advise you to visit a urologist in person first. Based on some evaluations, the cause of the problem can be known and accordingly the doctor may decide whether your mother needs surgery or medications.