So Confused and anxious. Someone please help

I’m 4 days late on my usually 30 days cycle. I took 3 pregnancy tests. All negative, even an early detection kind. My CM is basically dry. No PMS symptoms except acne and tender breasts, the latter beginning the day before my period was due. I’m used to both happening 3-4 days before. I do have stress in my life- transferring schools and family things. Could this really do it? I don’t want to be pregnant and I’m really hoping for answers and peace of mind. Unprotected sex occurred New Year’s eve/Day, 2/3 days after my fertile window ended an 3/4 days after i ovulated. I’m sorry for the guesstimate but when it’s New Years and you’ve been drinking 😅