Smoking marijuana can have adverse affects on a continuing pregnancy, but if you plan to have an abortion no matter what, it will not affect the success rate of the abortion itself. Other things you can try to help with the nausea is anything made from ginger (tea, candy, soda), taking vitamin B6, and trying (if you can hold anything down) to just eat small bits of crumbly dry food (like crackers). The nausea may continue for a while after your procedure until the hormones of pregnancy are completely out of your system. The provider who is doing the abortion for you may also offer prescription medication that can help with the nausea as an alternative. I hope this information was helpful and answered your question. Take care.