Why do my boobs hurt??

So I'm 4 month pp and I haven't breast fed at all since he was like 2 weeks. My milk dried up and haven't produced any since. I know it probably doesnt dry up completely but I havnt had any. So my boobs have been hurting the past few days and they feel bigger. Can this be my milk coming back? Even though I still cant get any out. Or does it sound like period or pregnancy?