Question: What is going on?

My last period was on the 15 th December. We tracked my cycle and did the deed on suspected ovulation days.
I missed my January period and after a week did a home pregnancy test. Which showed negative.
A week later another still reading the same.
I have now taken 6 test each a week apart all the same result.
I'm tired, sore breasts. Throwing up when I brush my teeth. Pain in my right side. Headaches. Moody.
Yet each test is negative.
I have now missed two periods.
I keep thinking maybe it is all in my head.
Had anyone else had this happen ? And what was the result??