It is possible, occasionally, to get pregnant after stopping
clomid. However I would recommend two other options. One is to consider a drug called
letrozole. Sometimes clomid, although it makes women with PCOS ovulate, causes the uterine lining (or endometrium) to be too thin to support a pregnancy. Letrozole does not have this side effect.
Another set of drugs to consider are injection fertility drugs. It is pretty common for clomid to fail - only about 50% of women who ovulate on clomid actually get pregnant. For those who do not get pregnant on clomid, the success rate with the injections is very good. The drawbacks with injections are: 1) you have to give yourself a needle every day, 2) there is a higher risk of twins, triplets, etc although if given carefully this risk can be reduced, 3) the injections are much more expensive than clomid or letrozole.
I definitely would not give up! There are other, very successful options, beyond clomid, which just does not work for everyone.