Sure, too much of a good thing is a bad thing. But I assume you’re not planning on stuffing your face with dozens of avocados each and every day. I wouldn’t worry too much about eating too many avocados. It’s full of fiber and really healthy. Just eat a few per week and don’t worry about it. :) 
As a guide, my family and I usually eat avocados maybe once or twice per week, and sometimes as much as 4-5 times per week.