Megan, I do not believe sperm life inside the female body is part of the accepted curriculum of US Sex Education.
Do you have Take Charge of Your Fertility? It would explain everything.
One factor in sperm living is the quality of female CM. In a hostile CM environment, sperm dies within hours. In fertile quality CM, sperm can survive up to five days. Every woman is different and would need to chart their CM to see if it's fertile quality or not, to be able to access likelihood of conception based on sperm survival.
The best chances for conception (if there are no infertility factors or history of pregnancy problems) occur on -4,-2,0,+2,+4 as related to ovulation.
That site will be able to answer the vast majority of your questions. Their tutorial on the female cycle is amazing.