Missed period and negative pregnancy test

Hey all. I have never missed a period and is very very regular. My husband and I have been trying to have a baby for about 3 months now. I am 3 days late for my period and have taken 3 tests since missing my period and all have come back negative. I’ve had some pregnancy symptoms, such as nausea, fatigue and back pain. Should I just wait a few days to see if hormone levels increase or see a doctor? It’s very frustrating not knowing what is going on with my body! Thanks in advance.