If I was never notified of extra fees and cost in addition to my fines, and my probation is expiring soon, how can they extend my probation?

I was sentenced to 2 days in jail and 11/29 probation. I have every court paper scored and nothing says anything about owing over $2000 in costs and fees. The only thing in my record says I owe $150 for paraphernalia charge and $250 for simple possession of marijuana. When I called to pay off my anticipated balance of $110, i was told I owe more than $1600. Now they want to extend my probation. Had I known about the added fees and cosrs, I would have paid more. This cannot be right. I have copies of everythung, nothing says I owe this outragious amount. I've recent found out I'm pregnant and currently in pregnancy leave. There is no way I can pay this now. What are my rights?