Spotting, missed period,negative test. Need advise!

I took a pregnancy test and it came back negative. I had unprotected sex while ovulating on the 4th. I used glow to record the lg surge, and it changed the date of when I get my period. I'm now three days late, and I'm wondering what to do. I took a clear blue test which said not pregnant. If I calculate when I should've got my period it should be not until the 27th. My last cycle ended on the 28th and typically I have around a 32 day cycle, but for whatever reason this month I had ovulation symptoms and an lg surge a week after my period. Any advise??!