Your refund should not be delayed because of the double filing, The processing of e-filed returns is pretty automated--done mostly by computer. So the timing of your refund should not be affected. You can check the IRS tool for the status of your refund: Where's My Refund
It may take the IRS a few months to get to your paper-filed return. The e-filed and paper-filed returns are handled by different departments in the IRS, and I'm not sure how much interaction they have with each other. If they send you another refund (from your mailed return) just send it back to them.
