Yes, they can blur some. Compulsive checking of locks and keys, and obsessive fears about legal consequences sound more like OCD. One way to tell the difference between the two is that people with OCD get intensely uncomfortable if they are prevented from acting - the obsessions get out of control. Those with OCPD are more able to tolerate not acting.

People with any anxiety disorder tend to feel more than their fair share of shame and embarassment, and it is possible to keep OCD hidden at times. Probably when you do what your thoughts tell you to do, the thoughts leave you alone for at least a little while, and you can probably act like it isn't affecting you for that long.

BTW, there is also a way to differentiate OCD from other anxiety disorders. People with anxiety worry, and one technique is to have them set aside 15 minutes per day for time to worry (and then when worries come up at any other time, they are to save it for the appointed time). Most people, even with anxiety disorders, will get tired of worrying for 15 minutes straight. Those with OCD usually get through 15 minutes of worrying just fine, and could keep it up for much longer without getting tired of it.