Should I be concerned if my blood pressure is 150\100. Today I took telmisartan 20. When will my blood pressure will be normal?

Unimportant. Try not to concern yourself with single readings -they have no physiologic significance. Instead, pay attention to averages. The more measurements you make, the more accurate the average will be. Measure when you've rested for at least 10 minutes. Be sure the cuff is large enough for your arm. Keep your arm at heart level. Ignore fluctuations - these are normal.