After Years Of Normal Blood Pressure Readings, (110-112 Over 72-75),

After years of normal blood pressure readings, (110-112 over 72-75), my readings recently have been low (e.g. 101/52. Should I be concerned about this? I am female Caucasian, age 78, take only 1 prescription medication (HCTZ 12.5 mg, 1 per day). Also take Centrum Silver and 4,000 units Vitamin D per day.) Lifestyle is rather sedentary. Thank you.