overdose by accident

Usually i take 500mg of Metformin am and pm. By mistake tonight i took another 500mg tablet, i phoned the GP who said it may make my bg levels a bit lower but is nothing to worry about as some people take 4 tablets a day.

Do you think she is right?

Thank you for the reassurance, i will sleep a bit easier! And will be more careful in future.
Debbie