Synchronicities with ex lovers

I had my heart broken about 3 years ago. Took me a long time to get over the person. Thought I had. I went to London to work for a week and was in a pub when an ex girlfriend of my old love walked past. I thought that was a real coincidence. Yet the next day (within the same 24hrs) I was in another part of london and she walked past me again! This freaked me out. The ex boyfriend then rang later that day.
I am lost. I still love him and he loves me but I am with someone else now who i also love in a different way. I know people change but don't they say you should never go back?
What is all this telling me?