So (ignoring unicode for the moment) you can send a message of 35 * 153 = 5355 characters via the Clickatell API. If you are sending unicode characters (which the OP is not) the character count for a single message is 70, reduced by 7 characters for each segment in concatenated message or 63 * 35 = 2205 unicode characters.
Lung-related causes. Many lung disorders can cause chest pain, including: 1  Pulmonary embolism. 2  This cause of chest pain occurs when a blood clot becomes lodged in a lung (pulmonary) artery, blocking blood flow to lung tissue. 3  Pleurisy.
Chest pain/discomfort/'slight winded feeling' needs assessment by a medical practitioner. There are multiple causes. Respiratory causes include a chest infection, asthma or clots. Cardiac causes include angina or inflammation of the outer lining of the heart. Sometimes it may be from acid reflux, or inflammation of the ribs, or there may be a psychological element.