What Causes Sick Feeling After Unprotected Sex?

Hello im just wondering i recently had sex with my friend early in the morning last saturday 3:00am it was afetr she sobered up from drinking, everyday since then shes been feeling sick, she is on birth control and i didnt ejaculate inside her, I couldnt do more cause of a heart condition, anyway today which is Tuesday she took the plan b pill early in them morning, now is it too early to detect pregnancy or is it something more severe other than pregnancy