Late periods are not listed by the manufacturer as a direct side effect of taking Clomid for inducing ovulation in women. A late period may indicate pregnancy, says About.com.
Most side effects of this medication are mild. Clomid may cause other abnormal menstrual bleeding, such as spotting, during a cycle. This does not necessarily indicate a problem or pregnancy, but a physician should be contacted for further evaluation, especially if spotting is accompanied by other symptoms. Headaches, vaginal dryness, abdominal pain, bloating and weight gain are all commonly reported side effects of Clomid, according to About.com. Women taking Clomid have experienced twin or multiple birth.