Period /late

Soo im about 3 days late this has happend before so it's nothing major  , I did have sex a few times this month and I've been getting cramps(not usual to happen when I miss my period)  and stuff im not sure if I'm pregnant, im waiting till a full week after my missed period before I take any tests! but I'm just wondering if normal period type of cramping is a symptom of really early pregnancy  or am I just stressing? lol.