When should we start freaking out?

Kaitlyn
Hey guys, I'm trying to find out when should I be concerned when TTC if it has been about three months and nothing, I'm following my little Green Day's and everything. I just don't know if this is normal. I was on the depo shot for 3 years but I've been off of it for 3 years I thought it wouldn't effect fertility but I'm worried it might have made things harder :( 
Trying to conceive our first baby💕