Sore boobs earlier than normal

I always have sore boobs 4-5 days before AF, although this month they have started at lot earlier, 12 days before expected AF.

We have been TTC for 13 months, so I'm over the "looking into every sign". But since this is a definite difference in my other cycles I wanted to find out if anyone has experienced this, especially anyone that has received their BFP.