Atenolol and Labetolol

I'm pregnant with an arrythmia and my OB changed my beta blocker from atenolol to labetolol, however I took one labetolol this morning and it had no effect in fact I had tachy all morning.  Rang the Dr and she wrote me a prescription for atenolol again and told me to take one but not take my evening tablet.  So I did and I felt fine.  But these evening I'm feeling a little rough and wondered if it is safe to do what I have done?

Took 1 labetolol 100mg this morning with food at 9am.  At 11am took 1 25mg Atenolol because of tachy.  It worked for the tachy but I am now worried that I was wrong to take two different beta blockers in the same day.  I'm normally on atenolol 2 x 25mg a day (1 am and 1 pm).

[Jerry_NJ]

From what I read you did what you doctor prescribed, so it should be fine.  It may take a day or two to get back to normal... give it some time and try not to worry.  

If new symptoms develop, call your doctor again.