I have a friend who had IVF and they did ICSI - where they inject the sperm into the egg. When they did that they found that her eggs had very thin walls. The doctor told her to get her mercury levels checked and she did and they were 10x normal. So - supposedly, mercury can affect egg quality. I don't know if it can be cleared up or if in fact the mercuryllevel was related to the egg wall thin-ness. I asked my doctor about it (we are scheduled to do IVF in April) and he said it has not been proven yet and that it was still being studied. So we hit a dead-end on the subject.
That being said, I asked my acupuncturist about mercury and she said you should definitely not disturb mercury in your tissues while you are pregnant. But she thought I would be ok to try a natural chelation product called NDF by BioRay BEFORE we do IVF and start medications, etc.
I thought I'd share with you. The product sounds interesting. I know that mercury detoxification is not a well-supported or understood process. I have no idea if NDF works, but I might give it a try just to see. I have myofascial pain syndrome - which is sort of like fibromyalgia in an isolated location (my shoulder). I am desperate to try things that might help, so I might try it.
Hopefully, this info will be helpful to you!
In addition - if you go to a fertility specialist and harvest your eggs (that's what you do for IVF), they can tell you about the quality of them. I don't think it's possible (we've done 5 insemminations so far, so I have learned alot about this) to know about your true egg quality until they see the eggs - which means they have to take them out of your body.
I suggest you consider the NDF and also see a reproductive endocrinologist. It's not a bad idea to get tested for general reproductive stuff early since you're 38. I got married at 39 and am 40 now, going on 41. It's taken us 6 months since we got tested and we're still not pregnant. So - you might be in a better position if you also know more about your reproductive health and your husbands. That might help you make a better decision because you'll know more about the timeframe you have, etc.
Hope this helps! and good luck!!