3 weeks is the normal amount of time to wait to be retested, yes. There's a possibility that you had chlamydia to begin with, which was cured, but that you also had something else, say mycoplasma or ureaplasma, which wasn't cured. So while your test might come back negative for chlamydia, that does not necessarily mean you might not have something else.
If I were you, I'd probably just get a urinalysis done. It will catch most (70%) causes of urethritis, and it's very cheap to do. You can get the results in a doctors office immediately. And I'd still get retested after the 3 weeks.
The symptoms I had after the last time we had sex which make me nervious was having to urinate a'lot. pressure at the tip of the penis. A little discomfort in my pelvic area..this could also have been from the sex before but it has been here for the last 3 days. The symptoms had basically gone away but about 13 days after treatment we had sex again and basically the next day I was feeling all these symptoms. I know that Chlyamdia usually doesn't react that quickly but I was tested for Gonnorrea and that was negative before. So i'm really unsure what the situation could be and I would like to get retested but they told me I need to wait 3 weeks after my last test. Is this accurate? Thanks agian.