It is not possible to get pregnant the day after intercourse, and it is generally impossible to determine pregnancy. Even if the first day of intercourse, the sperm and egg combined, combined with after the bed, need a process, the next day simply can not test whether the pregnancy. There are several possibilities for light bleeding. The most common one is probably cervical erosion, which is caused by the penis stimulating the erosion surface of the cervix after sexual stimulation, causing bleeding from the erosion surface, which may be a bit bloody on the second day. Another condition is the tearing of the vaginal wall, when the sex is excessively violent and there is not enough lubrication, there may be a small rupture and the next day when you wipe you find some blood in the vagina. So, if you see blood or redness the next day, it is usually caused by two reasons, and it cannot be caused by pregnancy.