Most miscarriages occur during the 1st trimester (first 12 weeks) of pregnancy, but can also occur any time during the first half of pregnancy. Most miscarriages cannot be prevented. It is often the body’s way of dealing with a pregnancy that was not normal. Just because you have a miscarriage, it doesn’t mean you can’t get pregnant again. If you have two or three miscarriages in a row, your doctor may want to do some tests to look for a cause or reasoning for the miscarriages. If any signs of a miscarriage occur, you should call your OBGYN. Signs of a miscarriage include vaginal bleeding, cramps during pregnancy felt low in the stomach (often stronger then menstrual cramps), and tissue or clotting passing through the vagina.