it's pregnancy category C, meaning it should only be used if the benefits outweigh the risks. so, if you are having severe severe pain that can't be treated effectively with tylenol, you are vomiting and losing weight due to the pain, or having some other major issues related to the migraines, then it is probably an appropriate decision. i would assume that your OB/GYN prescribed this for you, so if he/she feels it is in your best interest, i would be compelled to take it. i took it during my middle child's pregnancy briefly, but b/c it is actually a blood pressure lowering medication, i had trouble with it b/c my blood pressure naturally runs very low - so i was having some trouble with dizziness. my husband is a pharmacist and he was okay with me taking it(until the dizziness started), and obviously he wouldn't have been okay with it if he felt it was terribly unsafe. good luck and hope your migraines are better soon!