Sore breasts

Iveth
Hello, 
I been experiencing sore breast for the past week but its getting more intense 🙁 and my nipples are very sensitive hurts really bad i feel like scratching them too! Also i am experiencing cramps 😐 my last period was Nov 10 i am late but not surprice since i am irregular i dont know what to think and i am super scare to take a pregnancy test i took one las week and it came back negative 
Is anyone of you familiar with these symptoms ?