No show period Concerns

How many days after a missed period should I test for pregnancy. It’s only 4 days late but I am stressing out i had concerns about pregnancy before this and every missed day the more scared I’m getting. Im 17 in a few weeks and I haven’t had any symptoms of period, no sore breast which is always the case before my regular period.

But about two weeks ago my nipples were so so sore I could hardly touch them and that went on for 2/3 weeks. Am I over reacting???

Edit*** are sensitive nipples a sign of pregnancy