Trigger avoid inserting duplicates - sql-server

Question

I have created a trigger when a value is inserted to the main table dbo.MVF_Transport_Register, it updtes the dbo.MVF_Transport_Acc table with that record. Also when a value is changed on the main table dbo.MVF_Transport_Register it updates the particular field value accordingly on the other dbo.MVF_Transport_Acc.
Problem I have is: my trigger inserts duplicate records into the dbo.MVF_Transport_Acc table.
How can I amend this trigger so it checks dbo.MVF_Transport_Acc to see if the record exsists before inserting the record. If the record exists, it shouldn't insert duplicate records.
Can some one please check my trigger an advice how to sort this thanks in advance big help
ALTER TRIGGER [dbo].[UpdateTransport]
ON [dbo].[MVF_Transport_Register]
AFTER UPDATE
AS
BEGIN
UPDATE c
SET c.Record_Status = i.Record_status
FROM MVF_SYSTEMS.dbo.MVF_Transport_Acc AS c
INNER JOIN inserted AS i ON c.Order_No = i.Order_No
AND c.Record_Status <> i.Record_Status
WHERE i.Record_Status IN ('CONFIRMED', 'AMENDED')
AND i.Price > 0;
IF ##ROWCOUNT = 0
BEGIN
INSERT INTO MVF_SYSTEMS.dbo.MVF_Transport_Acc ([Order_No], [Record_Status], [Notes], [Transport_Supplier],
[Surcharge], [Vendor_No], [Pallets], [Amend_Pallets],[Price],
[Input_Date], [Amend_Price], [Transport_Invoice_No],[Transport_Job_No],
[Amend_Date], [Report_Price], [Return_Price], [Report_Date])
SELECT
i.[Order_No], i.[Record_Status], i.[Notes], i.[Transport_Supplier],
i.[Surcharge], i.[Vendor_No], i.[Pallets], i.[Amend_Pallets], i.[Price],
i.[Input_Date], i.[Amend_Price], i.[Transport_Invoice_No], i.[Transport_Job_No],
i.[Amend_Date], i.[Report_Price], i.[Return_Price], i.[Report_Date]
FROM
inserted AS i
WHERE
i.Record_Status IN ('CONFIRMED', 'AMENDED')
AND i.Price > 0;
END
END