I don't want to scare you. It could be your milk or it could be something worse. My friend was pregnant last year and noticed a lump. At first she thought it was milk ducts. The next month she noticed it was harder and had doctor check it out. Turned out to be breast cancer. In the end, everything worked out for her and she had a healthy boy.
You know your body the best. If something feels out of place get it checked out right away. If you're really concerned, call the doctors office. Most of them have a nurse you can talk to over the phone that will give advice until you go in for your next appointment.
How far along are you? It could be your milk ducts filling up with milk.
I think our names are spelt the same way... ;) anyways do the LPs hurt?...and is it just in one breast and where...