I found the solution!
After browsing through the addresses in the Electrum wallet, I looked for all addresses that have non-zero Tx value. I found the one holding BTG in the last address of the list located in Addresses>change>Used , it was the last one of them. And indeed that is the one showing up in the history of the last transaction of my wallet , in its detail's input tab.
View private key in that address , and then scanning from Coinomi, using "Sweet wallet got me the last amount before the fork of my wallet in BTG