"i am 21 years old and was on cyclen for 3 months when i was diagnosed with blood clots in my lungs (pulmonary embolism) i have since been informed that this birth control put me at a greater risk due to its higher levels of estrogen. luckily they were caught and time and i am currently being treated for them. my symptoms started out as a aching/stabbing pain in my mid/upper back that was worse when i ate, then a few days later my breathing started to feel rather heavy. i was also coughing and burping a bit. i also had a bunch of other side effects during the course of taking this pill including: breast pain, headaches, nausea and major mood swings!! i don&#039;t normally right reviews but i would feel horrible if this happened to anyone else!!"