Although an ectopic pregnancy does pose some risk to fertility because it can damage the fallopian tube, in most cases of methotrexate
treatment, the fallopian tube that contained the
ectopic pregnancy is found to be undamaged and open when a hysterosalpingogram (an X- ray test of the tube) is done about three to four months later.
http://yourtotalhealth.ivillage.com/fertility-after-methotrexate-treatment.html
Hope that helps and good luck!