3 days late

3 days late and have taken 2 test with BFN. Ugggh this is a terrible feeling I just want to know but I don't want to be disappointed with the bfn. But I have had what I think are systems very tired all the time, and hungry even after it have just eaten and headaches a mild cramps and sick to my stomach all day long. Thinking about going to an urgent care and getting a blood test to get answer but don't know if it's to soon for that as well and will get a bfn.