What’s going on?

Addy • 20, Single mom to my beautiful little girl Oaklee Celeste Mae ❤😘

I was massaging my left boob bc it started hurting and I felt a pulsing feeling. I thought it was my heart just beating until I felt the same pulsing feeling in my right boob in the same spot. Am I starting to lactate or is it my body just preparing for breastfeeding? I’m only 15 Weeks and 4 days.