I'm not sure if this is related to Singulair 5mg. chewable, ...

I'm not sure if this is related to Singulair 5mg. chewable, but now that I've been reading everyone's experiences, I fear that it may. My 7 yr. old has been taking Singulair 5mg chewable tablets these past 2 years. He takes it during the months of Sept. to October. His pulmonologist has not determined whether or not he is an asthmatic or not. When he would get a common cold, he would almost always cough as if he had the croup and he would need to use a nebulizer with Pulmicort. The Singulair worked great. He hasn't needed the Pulmicort for almost a year now and colds this year were limited to two minor sniffles. My son just started experiencing sharp pains on the left side of his chest. They would come quick and hard and disappear within 2-3 seconds. We immediately rushed him to the Emergency Room. He had experienced 5 quick episodes during Sunday, February 10th. The first 3 were spaced out about 20 minutes apart. the fourth was about an hour apart and the 5th and last occurred 2 hours after. The ER conducted a chest x-ray and an EKG, Neither showed any abnormalities. He felt a quick pain today, which is Tuesday. He has an appointment with a cardiologist on Wednesday morning. Now that I have read a number of postings, I am frightened. My son has not only experienced pains in his chest on the left side, but night sweats. occasional leg cramps. nightmares and is extra sensitive to emotional situations. I'm pulling him off Singulair. Last night was his last dosage.