Opioids are derivatives of morphine, a narcotic pain reliever. The term opioid generally refers to morphine and other opium poppy-based medications. Opioids work by decreasing pain signals being transmitted through the nervous system, which suppresses our perception of pain.
When you swallow semen, Semen and sperm go down into your stomach, where they are digested with all your other food. There is no passage connecting your stomach to your ovaries. You can not get pregnant from swallowing sperm. If the donor has no STDs, it is perfectly safe.
If the person that you are receiving the sperm from has aids or is HIV positive then yes you can. If you have a sore in your mouth or a severe dental condition (gingivitis etc.) then the risk of you getting aids is higher. Swallowing semen from a partner with aids also puts you at risk.