How can fibromyalgia affect pregnancy?

Meds? Fibromyalgia is not thought to have an adverse effect on pregnacy, although their may be some issues with medications during pregancy. Best to avoid them, unless signficant co-existent depression is there. Exercise daily, get good sleep, and talk to your doc about discontinuing meds or continuing meds.
Depends. Coordinate your care with all your physicians so they all know which medications your are on so that you can have the safest pregnancy. Your OB may recommend coming off your medications for the pregnancy, try to stay as active as allowed.