My phone has been sending text messages to people without having a conversation box.?

So i don't know who got this message. On top of that it says things I never wrote. In the message it looks like it was forwarded ex: then a written message (message contained info on a topic no one knows about). One of the texts were sent to me as if I texted myself??? I have Sprint with two droids on the same account. How is this possible? Is this a virus? I called Sprint and they're clueless to whats going on