Why is there a faint line in the second Prega news kit while there is a vertical line in the first one and pregnancy test is negative?

The reason for this is that before a period begins, a discharge of this nature is usually a result of hormonal changes. If you have been using protection during intercourse, then do not worry too much it is not always a sign of being pregnant. But if you are still worried, take a pregnancy test just to be sure everything is okay. 

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.

Experiencing light pink discoloration during your first intimate experience can be normal, often indicating minor tissue irritation or the breaking of a thin membrane. This can happen without significant pain and may not always appear as bright red blood. It's important to ensure you feel comfortable and relaxed during intimacy to minimize irritation. Should any unusual symptoms, such as heavy bleeding or persistent discomfort, arise, I suggest consulting a gynecologist for personalized advice. They can provide reassurance and guidance tailored to your situation.