Need advice

I feel like I need some peace of mind. Driving myself insane over here. My period for November was extremely long. 9 days. My standard is like 4-5 days. I’m pretty regular with around 30-31 day cycles. With my November period being longer then usual, I have no idea when I ovulated. My period was 11/25-12/3. My December cycle was suppose to start on 12/25. I had unprotected sex on 12/24 with no forms of BC. Well, my period never came on 12/25. In fact it was 5 days late. It started and was brown. Then red. Then pink. Then brown. Then red. It was all over the place. Not heavy. Never constantly. It would come and go. This went on for 4 days. 3-4ish. Now I’m feeling my my breast are sensitive. Not painful but sensitive. I have random waves of nausea. I’ve taken several test. Daily. All which are negative. Is this all in my head or is there a chance I’m pregnant?