What's the real deal with Caffeine?

I have read on a bunch of sites that caffeine is fine, one cup of coffee a day is ok.... but yesterday my doctor told me that caffeine is linked to a higher chance of miscarriages?
Is it that you can have caffeine when TTC, but not when pregnant? I am so confused....

ETA - the reason I ask is I get terrible migraines.. coffee seems to be the only thing that helps.

My doctor told me 1 cup is fine during TTC and during pregnancy but told me not to drink it every day.

I did end up cutting it out completly though.

Unfortunatly, I think that this is one of those subjects that many, many people have different opinions on.

Mr Dr never said not to have caffeine while TTC but I try to watch how much I have.

I definetly heard that while pregnant, especially the firt few months, not to have caffeine.

Thanks! I hear so many different things!