Sore Breast

Savannah • Newly weds! But have been together since 2006- found out in 2013 I had PCOS. Dealing with that and will start TTC soon!
Extremely sore breast for the past couple days. AF was 2 weeks ago this is my fertility window- Negative Tests/ what else would cause it? No nipple soreness just swollen/sore breast when touched/hugged/laid on - heavy feeling. Thanks for help!