Had my period on the 3rd and 4rth of April (2days) then today I went pee and noticed small brown blood in my undies? Normal or bad?

Normal. "darker blood" at the end of your cycle can be normal. It just means the blood has been in the vagina longer, similar to when you're cut fresh blood is red , but after exposure to air it becomes darker. If you are having sex, get std testing and an exam if you have pain with sex or urination, change in your normal vaginal discharge, odor or itching, a new sex partner, or sex without a condom.