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.
On the other hand, sperm survives up to 7 days within your body, and as long as you ovulate during the time that the sperm is viable, you can still get pregnant. This means that you have a fertile window of 6 days where you can ovulate anytime and your egg can meet the surviving sperm.