i take methotrexate (+ my copaxone) for the same reasons.
i too was very leary but agreed after i talked to my neuro several x's about it and we discussed the side effects and the low % of getting them.

of course, if i get them i'll really be kicking myself for MY decision.

i agree with the above advice.
it's within your power to say not at this time. you are a member of your healthcare team. you're the final decision maker.

AMN said it best.
also consider taking another advocate with you to the appt. you may feel better that way.

and, i hope you have no enhancing lesions.