I took amox during my pregnancy. I took 500 mg twice a day. However, I did have hyperemisis (extreme morning sickness) so for the first 5 months I could barely get down water and taking pills was not an easy task. I have a perfectly healthy 2 1/2 year old daughter now - totally lyme free.
It is a good idea to get on amox now while you are trying rather than waiting until you are pregnant. It is a good precaution. Do you have a lyme dr that can prescribe for you? I got mine from my lyme dr. rather than my ob.