Breast question

This morning I work up with my breasts looking slightly swollen and by tonight they were extremely firm and tender my boyfriend is trying to say it's an early sign of pregnancy because we are TTC currently and he wants a baby so bad and I just don't want to get my hopes up and I'm just curious about what besides pregnancy could be cause this issue because it is slightly freaking me out I also think it is way to early to have any signs of pregnancy I just think he is anxious haha