Regarding your treatment... Is your doctor sympathetic to treating Lyme for an extended time? If so, your doc could follow the ILADS treatment guidelines.
The species of Borrelia in Europe are different than the US. Even b.burgdorferi (the only species in N. America at this point) in Europe is more likely to cause neuro symptoms. Another species called b.garinii is also common in Europe and causes primarily neuro symptoms. While disease presentation is different with different species, my doc tells me that treatment follows the same protocol of adjusting meds based on the patients's symptoms and progress. (I asked because I have Aussie Lyme but live in California. I have neuroborreliosis.)
If you are not confident your doc can treat you successfully, or if your doctor wants to stop abx after you give birth, then you need to find a LLMD as soon as possible. You'll probably want to figure this out before the birth. I have read stories of women who had Lyme and didn't know it and really went downhill after giving birth, which is a big stressor on a body. You haven't been sick for a long time, so as long as you stay on abx, you should be in pretty good shape.
Here is the link to Dr. Jones website. There is some useful info on it.
http://www.drjoneskids.com/
Amoxicillin is the right thing for a pregnant woman with Lyme. You cannot take Doxycycline when pregnant.
I have heard many good stories of kids who got Lyme in utero who are doing great with antibiotics. Treatment makes all the difference. Planning to do the cord blood test is very wise. But if the baby tests negative, there is still a chance of infection. If s/he tests positive, then s/he will need amoxicillin. I have no idea for how long...are you aware of Dr. Jones in Connecticut? He is a pediatric Lyme specialist who probably does phone consultations.
My daughter was on a prophylactic (reduced) dose of Amoxicillin for just over two years to prevent bladder & kidney infections. She had no adverse effects at all. She also never developed a bacterial infection during those two years. :). I am sure killing Lyme requires a higher dose, but as long as there isn't an allergic reaction, amoxicillin is really safe.
Regardless of test results, you will want to watch for delayed development. Small children and babies cannot communicate what they feel, and so outward signs are important, even if they are subtle. A pediatrician's tendency to give a child time to grow out of a delay can be harmful in a case of Lyme.
You will definitely need more treatment after you give birth as just 11 weeks of amoxicillin after 5 months of infection has a good chance of leaving some bacteria behind. There is another Lyme mom on this forum (hopefully she will see this) who has recommended against breast feeding, as spirochetes have been found in breast milk. She had Lyme before she even got pregnant.
I think getting tested at IGeneX was an excellent decision! It sounds like you will be a good advocate for your baby!
Is that Cambridge in the UK?
Sorry, the questions and answers are getting jumbled. It all comes down to the same advice: find a Lyme specialist and don't delay.
I would start with the fellow at Cambridge and, if he doesn't treat, ask his office for a referral. Tell them how far along you are in pregnancy.
My friend never knew when she was infected. Many of us never do, because the ticks are the size of poppy seeds and many of us don't get the legendary 'bullseye' rash.
Too many MDs will not diagnose or pursue a diagnosis of Lyme without seeing the tick and the rash, but that misses many infections. That is why a Lyme specialist is so important to see and soon.
My friend didn't know when she got it ... many of us never do.
I never saw a tick or had a rash, and I suspect looking back that I probably had a low-level case of Lyme for several years, then got re-infected with Lyme and a co-infection (another disease the Lyme ticks also often carry) and that's when I got very ill suddenly. Everyone is different, the mix of co-infections is different, our immune systems are all different. I tried for a while to figure out the particulars of when and where I was infected, trying to make sense of it all, but ultimately I gave up and focussed on what infections I had and what to do about them -- the rest is a mystery, and one that (if solved) won't help the cure. So focus on the diagnosis and the cure looking forward, and for your baby, prevention or treatment in utero.
A Lyme specialist can say better what the chances are that the Lyme crossed the placenta to the baby, but what matters now is to take all appropriate action to treat and/or prevent infection.
Whether it's treatment or prevention mode, I don't know that the doc's actions would be different before the baby is born, but that is for a knowledgeable MD to say -- but this is a developing area of medicine and science, with much still being discovered. That is why I would find someone like the MD at Cambridge who thinks 'big thoughts' on these topics and is 'cutting edge' in the field.