Yes I have one. It's supposed to be first anniversary or first baby, whichever comes first. It came about like this as traditionally when a couple got married, they started TTC on the wedding night.
Mine is 18k gold with diamonds half way round it set in white gold.

I went and picked out and put a deposit on mine when we had been married only 7mths and told DH where to pick up in time for our 1st wedding Anniversary