Yup, if you have not, this is how:
Visit this website: Singapore Elections Department
Click onto 'e-services', and this is what you should see.
Login into it either by using your singpass or the issue date of your NRIC (this can be found on your IC).
Once you have login, verify the details of your name and address. If everything is right, logout and you are done.
You may submit a claim if any of your particulars in the Register is incorrect.
The importance of checking your details:
If you happen to have the intention to serve the people of Singapore as an elected MP that is to say stand for parliamentary election, you have to be registered.
And lastly, what are the chances of a snap-election this year?