I went to ER several weeks ago, as I thought I was having chest pains. Turns out it was nothing. I take atenolol 25 mg for fast heart rate and while in ER, they gave me 50 mg Lopressor (which I believe is metoprolol), one time dose of Lopressor. About a day or two later, I woke up in middle of night with elevated blood pressure and somewhat tachycardia. The blood pressure was higher than what I was used to and I attributed it to not receiving any more Lopressor. It took me about 5 days to not feel affect of Lopressor, and I only took one dose. BP hit 158/100, high for me. So, I would definetely check with your doc, to be safe. Hope everything works out.
You should call the office and talk to your doctor/nurse or your nurse will communicate this with your doctor and will call you back and tell you what to do. Don't risk it by yourself.