Miscarriages, also known as spontaneous abortions, are pregnancies that end on their own within the first twenty weeks of the gestational period. They are fairly common, with studies showing that ten to twenty-five percent of all pregnancies end in this manner. There are many different causes for miscarriage, including chromosomal abnormalities, maternal health problems, environmental exposures (such as smoking or alcohol), and other reasons that are not known. The chance of miscarriage increases with maternal age. Some reasons for miscarriage raise the risk of repeated miscarriage, while others do not have any impact.
As for not being able to get pregnant since your miscarriage, this can be due to several factors. Couples that try to get pregnant for a year without success should be evaluated by their doctors to discover factors that may be contributing to infertility. In many cases, education about the woman's ovulatory cycle and the timing of intercourse lead to success. If your periods have not been normal, then you may not be ovulating on a monthly basis.
You should talk to your doctor
about the symptoms you have been experiencing, the details of your menstrual cycle, and your desire to become pregnant. Your doctor can start with a simple history and physical, and then target any further testing (with blood work or imaging) to your individual story. Good luck.