What makes things worse is that you have your eye on a gorgeous brown rose gold diamond ring, and you are fairly sure he has noticed that. If you are waiting for signs that he is about to pop the question, look for the following ones.
A Sudden Interest in What Jewelry you like
Your guy probably does not give a jot about jewelry, which would be typical. If he starts asking about what you like in that department, there are few other probable reasons for it than the intention to propose.
Getting on your Computer
If you see him going through your web history or even simply using your laptop for a vague reason, he is likely digging for diamond ring ideas. If you want a specific one very badly, this is the time to hint at it during an unrelated conversation.
If he is avoiding spending time with you and this is unusual, he may be busy setting the stage for a proposal that will hopefully sweep you off your feet. Do not spoil this for him; let it play out, and enjoy yourself.