The waiting is hard, I know. When I was in your position a few months agao, my cardio ran down the possibilities and I waited for the TEE. The standard echo showed a spot in the left atrium.
1. Clot. No, because I'm already on Warfarin
2. Infection. Not likely because of lack of fever.
3. Tumor. That would be serious and the TEE will tell for sure. No heavy exersion until the TEE.
4. Nothing. That's what it turned out to be - an "artifact". Hope yours is too!
BTW, I think Lynn's question is a good one, because my understanding is that a positive culture is conclusive, but a negatvie one is not.
Is your TEE scheduled?