Hiya, really sorry to hear you've had such a bad time. I dont know anything about ectopic pregnancies I'm afraid, but the optimist in me first thought was that it could 've been an egg passing through the tube. I had Clomid to get pregnant and when I ovulated the pain in my lower sides (where my tubes/ovaries are) was awful.
I'd ring your Doc and try to get a scan or something to be on the safe side because you dont want it to get worse if it has happened again.
Hope all turns out ok for you.
L x