I had an ectopic pregnancy back in 2007 when I was undergoing IUI. I did an IUI cycle and on BT day, blood test was negative. The following cycle, I tested positive for OPK everyday for 7 days and finally I decided to do HPT and discovered I was pregnant. Went back to NUH clinic where I did my IUI and after several blood tests and scans over several days, we discovered the ectopic pregnancy in the right tube. Took an MTX injection and it was cleared. Since then I did several more IUIs and one round of IVF, all unsuccessful and I gave up in 2009.
Now 6 years later, I conceived naturally in May. When I first tested positive, I feared it might be ectopic again and had several blood tests to rule it out. Today I am 23 weeks.
So yes, one can be successful after an ectopic.