Warum habe ich nach dem Sex Bauchschmerzen?

You probably have a yeast infection. Yeast infections may be characterized by vaginitis and such symptoms as itchiness, pain, and discharge (whitish color, worm-like) in the vagina. On the bright side, yeast infections are common and can be easily treated with over-the-counter antifungal creams or tablets. It is necessary to avoid using sweet-scented products and wear cotton underwear to assist in the prevention of future infections.

A CA 125 level of 35.10 is within the normal reference range for most laboratories, as the normal range can vary slightly depending on the testing facility. Generally a value below 35 U/mL is considered normal. 
CA 125 is a protein marker that can be measured in the blood. It's primarily used as a tumor marker for ovarian cancer but it can also be elevated in certain other conditions.

It is necessary to take a pregnancy test if you had unprotected sexual intercourse and the delay of your period occurs. While a negative result and the absence of your period require an additional check with consulting either gynecologists or obstetricians. They can determine if there is an underlying condition responsible for the delay and offer adequate treatment

Pain in the breasts can have many causes, particularly in someone who has HIV. For example, it might be because of an infection hormonal changes, or inflammation. Your mother must go to her doctor as soon as possible so they can find out what is causing it exactly. To help deal with the pain and underlying problems she may need some drugs, changes in the way she lives, or further tests.