I am not convinced at all that this is IBC.
Remember, our breast are very tender, and it is possible that you made a turn in your sleep that caused the bruising.
Also, are you taking any aspirin or other non-steroidal anti-inflammatory medications? These or a lack of some nutrients can make us more prone to a bruise. Often a little collection of blood will occur under a bruise making a firm knot.
Although I know tha IBC is often not caught on exam or even mammogram until advanced, lets go over symptoms that do occur first in women with IBC.
This disease occurs when cancer cells block the lymph vessels in the skin of the breast, causing the breast to become red, swollen, and warm.
There is usually a sudden increase in breast size (one noticeably larger than the other)
Sudden warmth or heat that is felt upon touching the affected breast.
Constant itching or pain in the breast
Nipple changes such as suddenly becoming inverted or flattened or discharge from the nipples
Changes in skin of the affected breast such as thickening or ridges that may include dimpling that is textured and looks like an orange peel.
A chnge in the color of the areola.
One or more bruises on one or more of the breast that does not go away
Swollen lymph node or under the arm or at the neck.
This type of breast cancer is 10% of breast cancers in the U.S. (In Canada, only 8 % of total) - you guys are healthier!
From what you have expressed, I doubt you have IBC, and if you did, you have likely caught it very early.
So, please take some deep breaths, and if I were you I'd do some praying, and visualize this breast bruise and bump quickly clearing. I hope I don't bother you by saying this, but prayer has scientifc research that proves it works.
Also, make sure you drink plenty of fluid, this can help bruising to resove quicker, and so can exercise - exercise stimulates the circulatory system which allows the WBC's to carry away the debre of the bruise.
If you have questions, please ask.