TTC after nexplanon, miscarriage?

Ra
Hey ladies! 
My husband and I decide to start trying for our first little one recently. I got my nexplanon taken out a couple weeks ago and my doctor told me to wait to have my first period before we start trying because it will help prevent a miscarriage. Has anyone else heard of this? 
My period was suppose to start last week but seems to be delayed due to the birth control removal. 
We plan on waiting but I know some women wait a long time for their first period after birth control. Just looking for a little perspective as to what to expect. 
So glad I found this group for a little extra support!