Yes it is right for them to look into it suddenly, the sooner they check you out the better. It does not mean there is something really wrong with you, just that they want to make sure especially as you had a mild abnormality before. It is easy to say try not to worry, but that is the only advice I can give you. Sooner is better because at least it will be over with, and hopefully you will get yor results.
I hope that it all goes well for you, let us know how you get on.