I think that is a personal decision. If I am understanding your question correctly, you are asking if you should wait a few months and apply for the SSCP certification, of if you should immediately join (ISC)2 as an Associate?
I think the Associate program is great if you are short of experience for one of the certifications requiring more time in the industry, such as the CISSP or CCSP.
I don't know what tangible benefit you would gain for being an Associate for just a few months. Unless you are planning to change jobs during that few month window, and think the potential employer would be looking for that designation. Which I would think isn't common.
That is just my opinion. I don't think there is truly a right or wrong answer here. But, either way, good luck!