Pain in and under breast

Hi everyone,

I’ve had this come and go pain, sometimes every few minutes in my right breast, sometimes it’s under my breast or into my chest. It’s almost like a stabbing pain, I went to the doctor today and she felt for anything abnormal and said she didn’t find anything, I also had a pregnancy test and I am not pregnant. I’m 7 months pp if that matters at all, and also on my period and never had anything like this before on my period.

Anyone have any idea what it could be? I’m getting worried.

Thanks