Can I be pregnant?! Help

My Boyfriend and I had unprotected sex and he came in me on December 28th during my supposed fertile window and idk when I ovulated. I’m supposed to get my period today and I always spot the day before my period starts and I haven’t. I’ve been having milky white discharge and noticed some nipple and breast soreness & have been having on and off again light cramps on my right side and back. I took a pregnancy test 20 mins ago and it came back negative. Could I still be pregnant, should I restest or did I test too early ?! Help ?!