Can I use a regular thermometer to measure my pool temperature?

Of course you can. A thermometer is jus that to check the tempreture of just about anything. 

No, in many cases you can not. The best thing to do is purchase a good pool thermometer that will give you the most accurate reading possible. Standard household thermometers may not be enough or do the job like a specialized pool thermometer would. Here are a few to help you decide.