could I be pregnant?

Me and my bf did it on January 17 this was in my fertile window and he ejaculated inside me now I’m experiencing extremely sore boobs very tired having to pee a lot more often and for the past few days when I wiped it’s was a very small amount of blood on tissue it only happens once or twice a day and then I don’t have anything else until the next day I’ve also been having slight cramps could I be pregnant? Is this implantation bleeding. My period I sent due for 4 days and i never spot before my period.