After two miscarriages and IVF - we had one that seemed ectopic - couldn't find it anywhere on u/s, no villous found in uterus etc.

After one shot of methotrexate at an HCG level of about 6,000 it went down to 10 after about 8 weeks. Then it stopped there for 3 weeks and I had another methotrexate shot. Now, after 4 weeks it is still at 10. The doctors have no idea what might be causing this and there are no documented cases of it - therefore no protocol, no advice, no indication of if it might be Ok to TTC with a level that is still not considered "gone"....

Do any of you have any experience with this?