I'm on lovenox inj 2x a day and Coumadin (warfarin) for two tiny pe's. Can I develop another pe while on them. I had no symptoms of my first ones. I'm scared.

Pulmonary embolism. Can be fatal if they are big enough. When your doctor investigated its source, he probably could not find it, if he did not recommend any other treatment. You should be on anticoagulants to minimize recurrence. And you should stop taking any meds that might predispose you, such as birth control pills, and stop smoking if you do smoke. Talk to your doctor on how to minimize your future risk.