I had my daughter 18 months ago. She is healthy and perfect and tested negative for lyme at birth and at was re-tested 2 weeks ago and was negative so she is lyme free and just an angel. I was diagnosed with lyme 1998 after 5 years misdiagnosed. was chronic and very bad for 3 years. got better for 3 years. then relapsed and was on abx for about 8 months when i found out I was pregnant. I was terrified because I didn't know what role lyme may play in the pregnancy, but to be honest, the lyme seems to go away or into hiding during pregnancy. At least for me it did, but I was horribly sick with hyperemisis. Extreme vomiting and nausea. It wasn't an easy pregnancy for that reason alone, but I got through it, and now have my wonderful beautiful daughter. We are actually talking about baby #2 now for next year.
I had a great lyme doc and a high risk ob/gyn who watched me very closely, but they all told me that passing lyme onto the fetus was a very small risk. I was given amoxicillin but due to the extreme vomiting and not being able to eat or drink for most of the pregnancy, I was rarely able to take them or keep them down. It is a good precaution to take them.
I also breastfeed for 3 months. I felt amazing during those months too. Put the lyme almost into remission. Now, 18 months later, some of my symptoms are back so I am working on getting them gone once again.
I would not worry about passing lyme to the baby if you have good doctor's who will take care of you. The hardest part for me is being sick and taking care of an 18 month old. That is my only advice. I would never let lyme stop me from having a family or going after what you want, but it is a little bit extra work for those of us still dealing with this illness.
Good luck. I would tell you to go for it.