Why would I have another period right after one?

I have endometriosis, I know this. but, for the last six months or so, I have had consistenlty two periods a month. exactly two weeks in between. recently, I just finished my period and went in for an exam and the next day I started my period again. it started as a trickle and then became like a normal period after that. I have noticed in the past sometimes intercourse could also start my period. does this mean I have scar tissue in the vaginal region? or should I worry about cancer. My mother had uterine cancer. and I am a smoker. all the women I know who have had such irregular bleeding has had cancer. I have had my paps done regularly.

Dysfunctional uterine bleeding, specifically Metrorrhagia, can be caused by a number of reasons in both women with Endo and those who do not have the disease. Aside from Endo and adhesions, polyps, fibroids and infection, the most common reason for Metrorrhagia is hormonal imbalance. It can almost always be treated effectively based on the underlying cause, once the cause is diagnosed with certainty. You may need to undergo any of the following tests in order for your doc to have a better understanding of what the actual cause is:

Endometrial biopsy: sample of tissue from the inside of the uterus. The tissue is then examined under a microscope.

Ultrasound scan: Sound waves are used to get pictures of the uterus, ovaries, and pelvis. The ultrasound probe may be placed on your lower abdomen or into your vagina (AKA "transvaginal").

Sonohysterogram: an ultrasound scan is done after fluid is injected through a tube into your uterus. This test allows your provider to look for problems with the lining of the uterus.

Hysteroscopy: Your health care provider inserts a thin metal tube with a light and tiny camera through the vagina and cervix and into the uterus. This allows your provider to see the inside of the uterus.

Hysterosalpingography: Dye is injected into the uterus and fallopian tubes through the cervix. X-rays are then taken. The dye outlines the shape and size of the uterus and tubes.

Treatments aside from hormonal medication and laparoscopy to treat Endometriosis include a D&C, hysteroscopy (to remove a polyp, for example), and rarely, depending on the cause, a hysterectomy, which is removal of the uterus. In cases where cancer is found, it is treated accordingly (i.e., surgery, radiation, or chemotherapy).

Good luck and hope all turns out well for you.

It is a very common symptoms of endometriosis.

The only way to be absolutely sure is to ask your doctor. Are you old enough for menopause? I know someone who had continous heavy bleeding when going through the change.
Also, with some women, time in between periods shortens during menopause until it stops completely.