Glad to see you're already on your way to having this looked at. I personally don't recall anyone who had been diagnosed with TC as having first discovered a rice-sized/shaped lump. Most have described it as pea-sized for a reason, although I don't think it necessarily has to be round. For me, shape didn't matter so much as did size. What had started off as a small lump quickly swelled up to nearly the size of a racquetball, accompanied by a tolerable, slightly uncomfortable, dull ache.
As I tell most people, a very large majority of lumps and bumps are not TC, and while it's always smart to have it looked at by a doctor asap, I wouldn't get too worked up about it until something more than just the lump itself gives further cause for concern.
Let us know how your visit goes. Best of luck.
Dx Testicular Cancer (pure seminoma, stage I) - 5/2/2008
Right side orchiectomy - 5/6/2008
20 Sessions of Radiation treatment - 10/2008
Remission 4 years
Low Testosterone - 5/2012 (treatment postponed)
Dx Thyroid Cancer (papillary carcinoma) - 6/21/2012
Total Thyroidectomy, lymph node removal, trachea scraped - 7/18/2012