Somethings wrong with my blog

I am new to wordpress. I recently bought hosting and a domain. I just shifted my blog from blogger and doing some checks to see if all my posts were ok. My blog homepage was ok and suddenly the weirdest thing happened. My first few posts have the same font and size but after some posts later, the size, font are different and it changed my page design. Can someone tell me whats wrong? My url is http://www.bdpollution.com

thanks