As long as you keep contributing to your CPP, you'll will increase your retirement income when you stop working. Also, if you have an employer, then they have have to keep making their portion of the CPP contributions.
However, depending on your situation, the benefit you get from continuing to contribute might not be worth the amount that you lose on your income now, especially if you are self-employed. So, I would recommend speaking with someone who is knowledgeable in the subject to help you decide if you should stop or not.