On Sunday evening I found a lump in my left breast that is hard as a rock and doesn't move (I've tried) and it is hard to figure out how big it is because I can't find the edges of it on one side so it doesn't appear to be round. It doesn't hurt at all and I don't know what made me check but I did. I just finished my period so don't think it is related to that; I'm 34 years old with a 5 & 6 year old. I went to the doctor on Monday who agreed that it was a lump and wanted me to get a mammogram and ultrasound done as soon as I could get in at the local breast cancer center. Unfortunately, it isn't until next Wednesday so I am left worried until then. What else could it be? I know the odds are definitely in my favor since I am still young. What is the difference between a breast cancer center for a test versus a regular x-ray location like most of my friends have gone to.