Hello Melissa! First, cudos to your fil and to you for listening. It is so important, no matter what age you are, to do the sbe. Okay, now take a deep breath and try and relax.
I don't know if there is anything to worry about but I do agree w/ your husband. Please call you physician first thing and get an appointment. Have you had a mammogram before? I was asking because of your age. If your physician tries to tell you that there is nothing to worry about, I would strongly suggest telling him that you would like to decide that yourself after an exam and a mammo. If he still doesn't want to see you, then call your obgyn or another physician. It is always better to error on the safe side.
Please keep us updated and don't hesitate to post if you have any other questions.