Have you purchased population upgrades for your planets?  New planets cost money to support until you've purchased population upgrades for them.  Full-sized planets need two population upgrades to get rid of this underdevelopment penalty, while asteroids need only one.

It is either no population upgrades for planets or autocast Vasari minelayers as Darvin and Kitkun have mentioned.

Hmm... I'm not sure what this was then. I was playing advent and I had two or three hanger defenses out there and I had put the mine-laying planes on autocast.  I was experimenting with the mines.  Could that be it?

The other thing is that I did not have all of my planets fully upgraded.  So if that takes money in chunks that could be it. 

I was using the Advent progenitor to colonize worlds and then buying a lot of upgrades.  Is it possible that some of those upgrades did not go through (get built) until later (because I clicked like 4-5 planet upgrades at once) and that when the world(s) were finally upgraded the discount price (from the Progenitor's colonize ability) was no longer good and the difference in upgrade cost was taken out of my bank?

Thanks for the replies everyone. 

You dont need planets fully upg to stop loosing money 1 upg for roids and 2 for all other planets

Ding ding ding!!  This was definitely it then.  Thanks all!!