Periods Late by 6 days

Hello All,

I generally have 31 -32 days cycle and last period I had on 12/26. And had unprotected sex on (1/6) 12 th day and on 16, 17 th day,for the first time I had spotting of dark red blood when I wipe with tissue . I assume it was ovulation spotting. I was suppose to start my periods on 1/26 and it hadn’t started yet. Done 3 pregnancy test (one on 1/25,1/29,1/30) all came negative.. So late periods actually is stressing me out .. Anybody have any idea what is happening would def help me ..This is happening for first time.. was planning to have doctor appointment sometime this week .. So do I need to take appt with general physician or gync..

really appt ur response thanks ..