lobular carcinoma can be difficult to detect. They want to do the MRI to get a better look at it before doing surgery. For example, MRI's are good to tell if it is unifocal or multi-focal - that is, is there only one cancer or more. Probably it is only one, so don't worry. They just want to double-check. MRI's don't hurt - just the IV for the dye they use, and that is minimal - like getting blood drawn.

Talk to other people you know who have had breast cancer, if possible. One out of 8 women will be diagnosed in their lifetime with BC, so it is likely you know someone. This forum is also good.

Are you going to one cancer center or medical center for all your treatment? You will see a surgeon, an oncologist, possibly a radiation oncologist. If so, ask if they have a nurse navigator to help you. Also ask if they have counseling (social worker, therapist, etc.) to help you sort our your feelings. I wish I had done this when I was first diagnosed.
If you can choose all of your doctors, that is nice, but you may be on your own for someone to coordinate your care. Ask your doctors if they can give you any assistance in this. You might also check your insurance to see if they offer care coordination. Some insurances do. Don't hesitate to ask for a second opinion if you feel that you need one. Don't be embarrassed to ask. It is your right.
I pray for peace of mind and calmness for you.

@catlover2020, how did the MRI go? How are you doing?