4 days late negative preggo test?

I took a test on day 3 in the morning with a First Response and it was negative. I have 33 day cycles and we bd'd around ovulation time. My last period was on February 23rd. The only symptom I'm having is fatigue. Which I usually get around af. I was cramping a little bit two days ago before I went to bed so I was sure I was gonna start. But since that nothing. I'm gonna wait a week and test again and it still nothing gonna make a dr appt. Anyone had this happen before and turn out to be pregnant? I'm not under any stress and nothing has really changed in my life. I know it's normal to have an off period every now and then but I'm just hopeful. I really want to be preggo!