Sore Boobs

Dajah 💁
Okay so my period is over. My boob's still get off and on sore or tender. I can't put my finger on what can cause this except pregnancy. I don't think I am though because I recieved all due periods since last engaging in sex back in Jan and took a pregnancy test 3 weeks after having sex that came back negative. So Is there a such thing as post period symptoms?