severe breast pain a week after last period ended.. help!

Ashley
Okay so period was the 6th 7th 8th and 9th. My boobs started hurting to the point where I couldn't wear a shirt if I could help it at all on the 14th and now it's just my nipples. But they are so swollen and sensitive and hurt so bad even from just the fan blowin on them that it makes me cry in pain. I have gained almost over a cup size from swelling. I'm not supposed to start my period again for another 15 days from now. Why would my boobs hurt so badly and what in the world can I do to help with it?  
Side note: we have been trying to conceive and found out I have mild pcos. I was put on metformin 1000 mg three months ago. Normal periods have returned and my cycle is about 29 days on average.