Surprise from the boyfriend?

So my boyfriend and I tell each other everything and lately we have been talking about promise rings and stuff. Today he was saying that he spent money on something and refused to tell me and that instead of making him give payments they charged him the full price and he would have to email the people who did it. I feel like it might be a promise ring and our 2 year anniversary is in 14 days.  I'm just not sure though, id hate to think he is keeping secrets from me.