What Causes Lumps In The Breast?

My LMP was June1. I have taken both lisinopril and alprazalom (not at the same time) to help with Increase in BP (reactive to stress at job) until I could be transferred to another office. I also had a diagnostic mammogram on June 21 because of a lump in my breast. I got a positive test result from a home pregnancy test. Have I harmed my fetus is my question?