How should you know if birth-control give you blood cloths?

Blood clots and BCPs: Abdominal pain, chest pain, headache, blurred vision, and swelling in the thighs or legs may be serious signs. Often in a leg clots may be silent or cause only minimal symptoms.Suspicious symptoms are swelling, warmth, pain or tenderness. The pain may be in the calf or thigh and may be present only when the affected area is touched or when walking. Smokers and high risk patients should avoid them.