Yes. There is no medical reason why you cannot have sex during your chemotherapy treatment.
Many breast cancer patients experience little or no change in their sexual desire and energy level. Even though there is no physical reason why you cannot have sex, you may find your attitude towards sex has changed, however. Some breast cancer patients may find that their sexual interest declines, because of the physical and emotional stress of having cancer and getting chemotherapy.
On the other hand, you may discover that intimacy takes on a new meaning and character. Hugging, touching, holding, and cuddling may become more important than intercourse. Remember that what was true before you started chemotherapy remains true now: there is no one "right" way to express your sexuality. Itís up to you and your partner to determine together what is pleasurable and satisfying to you both.
Some doctors recommend that in the first day or two after your chemotherapy treatments, that your partner use a condom when you have sex. A condom protects the penis from your vaginal secretions, which may contain a very low level of chemotherapy drugs.
Also, because chemotherapy may have undesired effects on fetal development, it is recommended that an effective means of birth control be used during treatment to avoid both becoming pregnant and the possibility of exposing a fetus to drugs that can cause birth defects.