Ttc, 8 days late, negative test.

I am currently trying to conceive 2nd child. Last month period started the 22 and ended 26. I had sex on oct. 3 and oct 7 and 8 . I should have started period last monday the 20. However never did and 3 tests say negative. Should I wait a few more days and retest? Call for blood test? I am so anxious but dont want to stress about it. Any words of encouragement.?