Clomid (clomiphene) helps women unable to conceive a child by stimulating a release of specific hormones responsible for causing ovulation (release of an egg that is later fertilized by the sperm). Clomid can cause vision effects that may prevent you from doing certain tasks that require alertness and concentration. Make sure you avoid driving a car or operating machinery when on Clomid to avoid these effects. If you are pregnant or breastfeeding these are direct contraindications for taking Clomid - this drug has been classified as FDA pregnancy X, which means it is extremely harmful for the health of an unborn or nursing baby. Clomid can cause life-threatening birth defects and it's therefore important that you use two reliable methods of birth control. You can discuss your choice of birth control methods with your doctor in advance to make sure they are efficient and you will not get pregnant. If you think you may have got pregnant, stop the treatment immediately and talk to your health care provider to learn about your options. The symptoms of Clomid overdose include vomiting, nausea, abdominal pain, flashes and visual spots. In case you have these symptoms seek emergency medical help to prevent the situation from getting worse. Any side effects you develop must be reported to your health care provider to see if a dose adjustment is needed. The most commonly reported ones include headache, flushing, swellings, nausea, vomiting, diarrhea, breast tenderness, abnormal uterine bleeding, abdominal pain, swelling or tenderness. If you develop any symptoms not mentioned here please report them to your doctor as well.