It's unfortunate that you are suffering from this problem.
Fibromyalgia is a multi system disorder which affects the nervous system, immune system, hormones etc.
And the patient usually suffers from pain, weakness, severe and easy fatigue.
Fibromyalgia doesn't affect the fertility of a women in anyways, but since the intercourse can be a little extra painful, usually such patients tend to indulge less in the act.
However, once pregnant,
You can have a normal pregnancy.
But your baby can be a bit smaller or you may suffer from amniotic fluid problems.
Although it's not shown that fibromyalgia patients are more likely to go for a c-section than the other.
As the pregnancy may progress, you may feel a lot of discomfort and pain.
The medications of fibromyalgia are not advised in pregnancy, but lot of different methods like yoga, stretching, warm water bath, hot water bath tub could help you with coping with the symptoms.
Once you have delivered, you may not be advised to nurse the baby while you take medications but for information regarding that you will have to talk to your physician as he knows what medicines you are on.
All the best.
Hope you have a happy pregnancy.