Possible miscarriage?

I was concerned that although I have had unprotected sex for 5 years with 4 different men, and have no sexually transmitted diseases, I have never gotten pregnant. At times I will miss my period for a month, possibly two, but it always returns. Usually after I miss it, when it returns it is unusually painful, but if feels like painful cramps, not contractions, and I get no unusual discharge. Although my family has a history of gynecological problems, including trouble conceiving, and ovarian cysts, it has never been too terribly difficult for them to conceive. Are these miscarriages?

They could be, but there is no way to be certain at this point. It could also be some minor disruptions in the menstrual cycle that are common in late adolescence.

What should I do next? I am really not interested in conceiving, but this problem concerns me. Currently I am 21, married, and began my period 2 months before my 11th birthday.

Infertility is defined as no pregnancy after 1 year of regular unprotected sex. If that is the case for you now, you would be eligible to see an infertility specialist for evaluation.

Are you on birth control now? If not, take one of the home pregnancy tests next time you miss your period by 14 days or more. If it is positive, you should see a Ob/Gyn. Tell him/her about your past experiences. That is because spontaneous abortion or miscarriage is more common than people think. So causes for it are not routinely investigated until the woman has three or more in a row. If you are using birth control, wait until you are off and are trying to conceive before trying the above.

REFERENCES
a listing of scientific articles and texts used.