Returning to previous fitness level after injury

[Deleted User]

Ok folks. I did the Great North Run (first half marathon) in 1.53.15 which I was delighted with. Four days later I tore my hamstring playing football and have been having to take it easy since.
Nearly six weeks on, I am starting running again and have only done a 2-miler and a 3-miler (at slightly slower than my half marathon pace).

How long roughly do you reckon it will take to get back to where I was?