Usually with an increase in systole metric indicates a high resistence the heart is pumping against and the underlying cause can be atherosclerosis (vessels lose its elasticity and plague buildup). If you have been taking the medication more than 2 weeks, you may need a change of medication or an increase in dosage. Systole pressure is the pressure at rest and not effected be vessel resistance.
Often if there is chest pain (angina), the pain subsides almost immediately with rest from the exertion that caused the pain. However, there can be chest pain both with or without exertion. You may want to discuss the matter with your doctor expecially if you have shortness of breath as well.