is plan B actually bad to take more than twice in your life?

I was looking up information about the Plan B pill online and could only find that there was no lifetime limit on the amount of those pills that you can take. However, on here when I've seen posts about Plan B there will typically be one person commenting about how you're not supposed to take "x" amount of them in your life because it will screw up your fertility and periods. I was hoping someone could give me a source on this information. Thanks!!