Over time, chemo drugs have been improved, refined, and designed to cause less drastic side effects. As far as sex goes, some people carry on as normal, while others find that the chemo alters how they feel emotionally and physically.
Chemotherapy is also often given on an intermittent basis and once the side effects have worn off between sessions, your sex life should not be unduly affected. Although you may feel a bit tired and not always in the mood for active sex, this will pass as you grow stronger.