8 days late but negative test

Natalie

It's been 3weeks since ovulation, I am 8 days late, but I am testing negative. I have had light cramping since ovulation. Should I test again or wait for a period? I am afraid to get to excited.. with my first child I didn't test until i was 5 weeks pregnant and it had a very light positive line. Could it be the same wait for hcg to build up?