Fertility medications that are given can cause mood swings, hot flashes, headaches, abdominal pain and bloating. In rare cases there can be severe symptoms like nausea or vomiting, shortness of breath, decrease in urinary frequency, dizziness, weight gain in 3-5 days, severe stomach pain and bloating. Potential side effects after having IVF treatment are: passing of the tiny amount of clear or blood coloured fluid, mild bloating and cramps, tender breasts and feeling constipated.