Problem in yawning

[77kew]

I am 39 years old working in a company in finance dept. Over the last 6 month i have been doing aerobics and yoga and feeling fit and fine throughout the day. However over the last three days i am feeling that there is problem in yawning where i try to complete it but could not do it. I have searched in google and understood that this could be due to anxiety. i know that in last three days there is some issue with me where i am concerned and thinking over this. however i am not sure whether this is the only reason for getting problem in yawning. i do not find any problem in normal breathing even during aerobics which i do every morning.
I am concerned now infact on problem in yawning and not over the matter which was there three days which might have caused some anxiety

Please guide me how to tackle this issue