You say you guys are happy and in a happy place? The only reason you feel jealous or low about it is then because you are comparing your place to someone else's. I mean, if none would announce their engagements, you wouldn't have anything to question your own place.
However, if the issue is more like you are insecure rather than jealous on the fact you two don't speak about the future, then the issue is not being engaged and etc.
Ask yourself whether this is an issue created by an external impression of your own situation or an acutal internal dissatisfaction. If he's the one, then, all you have to do is be with him, which you are, so enjoy.