Sex doesn't routinely cause vaginal tears or bruising, and pain or bleeding should not occur after sex. Generally speaking a women’s vagina is elastic, with moisture that increases with increased friction, and thus sex is not usually going to cause tears or cuts that can be felt. If a gynecologist takes a microscope to the tissue relatively soon after sex it’s not uncommon to see microscopic tears that wouldn’t be seen on regular examination, and for the most part are not painful. But tears that are painful, along with abrasions and bruises can occur during wanted, consensual intercourse.
Exactly the location of the tearing or bruising will be more related to the position the male was in. Tearing and bruising is more common if lubrication is poor, often from not enough time for arousal and enough lubrication.
In some cases, particularly if a woman has a minor vaginal infection or extra dry due to her hormone state, irritated by condom use then the arousal of sex may cause swelling of the tissues, and if swollen, and a bit dry it can cause a tear. The feeling of pain with intercourse, especially in the lower portion of the vaginal opening is the most common sign of tearing during sex. Other signs of a tear from sex can be painful urination or spotting after sex.
Unusual discharge and odors are more typical from infections rather than tears from sex. Tampons, vaginal rings, and even biking can make a little tear into a larger more painful one. Rarely the tears will get infected, but mostly they just need a little time to heal, and some very basic care. the tears themselves thus are not medically an issue for the most part, because they do heal so rapidly, but they can make you more at risk for contracting STDs, so it's not as healthy if this is a regular problem.
If you have bruising or tearing you should see your gyno to make sure that is the diagnosis. If you just are getting a bit dry, low in estrogen, or have weakened pelvic tissues due to a varietie of issues, you may need healing therapies, There are many treatments, and the newest are using the MonaLisa Touch, ThermiVa, or vaginal PRP therapy.