Many Sellers will ban you as an Affiliate for purchasing through your own link, as they view this as fraudulent.
If there is a discount available, the Seller will have a special link set up. Contact the Seller directly to ask if they have any specials available to Affiliates.
On many networks, commissions are held until multiple sales are made. This ensures that affiliates are not circumventing the system and purchasing products through their own link. If you have a valid sale and the Seller believes you made the purchase yourself, you should contact the Seller and explain your promotion process, provide stats or other information confirming the validity of the sale.
The seller can also see the IP address of the sale. For further assistance in providing proof please contact Support and we will provide you with any supporting information available.