I went to see my dr and my bp was 140/90 then he took it 5 min later and was. 138/92 told me to come back in a month should i be worried about how hi?

No: Your BP is upper limits of normal to slightly elevated. Check it at home and monitor it.

Not severe: Your blood pressure was a little high, but not really emergent that you are at risk for stroke, etc. Long standing blood pressure can cause problems in the future though so it is important to have it lower. Generally, a dr. Will counsel you about less salt, stress, caffeine, and a better diet, than re-check in 1 mo. If high a second time, you may need medication. Best wishes.

High blood pressure: Yes you should be concerned and follow up on this. I recommend you by an automatic blood pressure testing device available at your drugstore. Start taking daily blood pressure reading, morning and evening and record them along with your pulse rate. Take this information to your doctor on next visit.