They occur about once in every 1500 pregnancies. Kidney stones cause severe pain in the back or lower abdomen. They may also be associated with blood in the urine. A kidney stone during pregnancy can usually be treated with pain medication and by drinking lots of fluid. These emotions are typical at this point in your pregnancy.
Most authorities believe they occur from the hormonal changes that continue throughout pregnancy.
There is little you can do about periods of moodiness. If you think your partner or others are suffering from your emotional outbursts, talk about it with them. Explain that these feelings are common in pregnant women. Ask them to be understanding. Feeling emotional is a normal part of being pregnant.