Atenolol harmful to fetus?

I take 25 mgs. of Atenolol twice daily for PSVT (paroxysmal supraventricular tachycardia: two episodes - #1 HR 242 bpm, #2 HR 208 bpm) I have read that this medication can be harmful to a fetus. I am getting married in May so I do not want to remain on this medication if there is a big serious risk if I were to get pregnant. I can't necessarily go off the medication because of my severely high heart rate. I want to know if there is another alternative. Another kind of med. perhaps? I'm also concerned about how my heart rate might respond to being pregnant. I will have the greatest opportunity to see a Dr. and have this switched now while I'm on vacation from school. Once I start school again, it will be very difficult for me to get this taken care of before I get married. Thanks!