Hello Kayleighmc13 and thanks for posting, 

I am sorry to learn about your mam and that you are experiencing these unexplained symtoms.

Because you noticed it in both breasts, I think the tenderness is more likely to be hormonal and probably not related to the lump. Breast lumps have a number of causes and although I can't say it isn't cancer,  it could just as likely be something else like a fatty lump, but obviously it is important to get it properly checked out.

I assume that you have been referred to a local NHS breast clinic. This is where any sort of breast problem is assessed. At the clinic they usually do ultrasound scans to check out a problem in younger women as they work best in this age group, so I am not sure if you will necessarily need to have a mammogram.

Naturally something like this is going to be worrying until you know what the score is and with your mam in your thoughts,  I expect it will be on your mind a lot.  Try to take things one step at a time and hold your nerve (not easy I know). Don't be tempted to look for answers online as the searching can make you worry more without leaving you much the wiser. 

I hope you get your clinic appointment through soon and that this just turns out to be a health scare. 

Best wishes,

Julia