Question … could be

Had on sex with my current partner on Dec 8 & that was during my ovulation period. But it wasn’t my actual ovulation day even though it is still counted as my fertile window. Anyway, I’ve been feeling nauseous for about two-three days now and more sleepy too… could this be an early sign of pregnancy? My period doesn’t start until the 26th and I haven’t taken an test yet. Plus, one of my breast was tender towards my collarbone but i believe that’s due to me laying down wrong because my upper back is tender too. Especially when I raise my right arm. Anyways…. Does all of this sound like I could be pregnant/ early signs of pregnancy?