lining not ready- postpone transfer

We were set to FET sometime next week. I went in for a lining check today and they said my lining wasn't quite as thick as they wanted. (6.3 and they want 7 at the least) I know, not the end of the world but it threw me for a loop. I now have to add in taking estrace vaginally until my next check next Friday. And transfer is postponed at least a week. Anyone have a similar situation happen with them?