It is never a good idea to stop pre-existing medication! Continue your dosage until you speak with your doctor. I know quitting some medication(but not all) meds can cause miscarriage, especially if you have been on them for any length of time. If you can not get in to see an obgyn soon, make a point of seeing your prescribing doctor as soon as possible to discuss any concerns. Hope this helps!
Try calling a free nurse hotlines or something if you don't have access to a Dr. This is a question that the wrong awnser could have serious consequences.