This is what I know now and wish I knew then.
I never had my mammograms in the same place.
In addition to getting your mammogram, it is extremely important for the radiologist reviewing your current mammogram xrays to COMPARE them to your previous mammograms. It is important for them to know what your "normal" looks like. If something unusual FOR YOU is detected, further diagnostics can be recommended. Didn't know that. Never had them compared.
Regular screening is still the best way to find breast cancer early, before any symptoms and when treatment is usually most successful. Even so, know your breasts. Know what they usually feel like and look like. Be aware that during your menstrual cycle, your breasts can feel more lumpy and tender, but don't hesitate, if you notice something different, notify your health care provider. Be diligent about examining and looking at your breasts.
The kind of breast cancer I have, invasive lobular carcinoma, is not usually felt as a "lump" and is often not detected by a mammogram until the tumor is larger. There are several new reports suggesting women with dense breasts have a higher risk of breast cancer. It's not that having dense breasts leads to the cancer, its that the "masking" effect of fibrous breasts can result in cancer not being detected on a mammogram.
I was always looking for a lump. That said, I was still the one that detected my breast cancer.
What I noticed a few months before I said anything is during my menstrual cycle, my left breast had an area that seemed harder than the rest of the breast. It was not until I also noticed my nipple looked different, as if something was pulling on it from the inside, that I became concerned.
An inverted nipple can be a sign of breast cancer, unless you were born that way. Didn't know that.
I also experienced an itchy feeling in the area that I NOW KNOW is where my tumor was located.
An itchy breast or nipple can be a sign of breast cancer. Didn't know that.
This is from the Susan G. Komen for the Cure website. It's an interactive tool you can do on your computer.