It depends on your hosting situation, but unless you're using a hosting plan with bandwidth allotments from like 1993, you definitely don't need to worry about that. My host gives me like 2TB of bandwidth per month for $10/mo, and even with an article with several images hitting the front-page of HN for a full day, I think I used less than 1/3 of that allotment.

And unless you're doing something really... bizarre... no one is going to spend their resources to DDoS your personal blog :)