More undergrad or...?

I have read hundreds of blogs on here, including all that relate to this question. However I was hoping for more guidance. I am a biomedical engineering student starting senior year and will probably graduate w/ 3.2. I have strong EC (shadowing,research,etc). I was thinking it would be better to do a 5th yr of undergrad, increase my GPA, and double major in biology, especially since I have only taken 1 yr of bio and would have plenty of more classes to take. Is this a better option than... More undergrad or...?
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums