Yes, I did have a lump. It felt firm, I'd say more like a dried pea than a carrot though!! I don't know whether a cyst would feel more squidgey or not, my GP thought mine was most likely a cyst but fortunately referred me urgently anyway.
It seems to me, the only way you can tell for sure what it may be is mammogram, ultrasound and if necessary biopsy, so perhaps you should try not to think too much about how it feels, as you can drive yourself mad doing this, with no resolution. If the doctors could tell by feeling it, you would not have to have the other tests.
I know it's a worrying time and each day feels like a week but the appointment will soon come round. The chances are it will not be cancer and you can heave a huge sigh of relief. If the news is not so good, your team will look after you..you kind of get swept up in the treatment and before you know it you are out the other end!
My treatment finished four weeks ago, (apart from five years Tamoxifen), but in January I was in exactly your position and I would say the worry before diagnosis is the worst bit.
Take care of yourself and remember to try not to google...I've scared myself silly by not following this advice!