There Is A Very Small Chance That I May Be

There is a very small chance that I may be pregnant. However, I cannot take a pregnancy test yet because I am still 8 days away from getting my period. My concern is that I am on 40 mg of Vyvanse. I need to be able to focus and pay attention to detail for my job. IF I am pregnant that I am in the very early stages of it, could I continue to take my vyvanse for another 8 day until I can take a pregnancy test?