You didn't say what market you are in. States have different laws regarding what an agent can reveal and not reveal. While I know it sounds fishy, what does your realtor think? Do the agents know each other? As other's suggested, I'd stick with my offer and let them deal with it and see what happens. You'll find out if it was a bluff. Although there are times when a buyer will "say" they're going to make an offer at such-and-such a price and then not do it. So ask if the offer is a written offer. In Florida, an agent can reveal some details (with the sellers permission) if he(or she) thinks it will help the seller. But generally speaking, most agents won't lie about what's on the table. They may fudge a bit - "I "think" I'm getting a contract close to list."
And in terms of being "aggressive" - what is it that your agent is not being aggressive enough about?