bad connection?

I'm putting in a shower with a 3" drain and noticed that the 90 degree fitting that goes up to the drain was not connected all the way in to the drain pipe. There is about a 1/2" gap between the lip of the fitting and the end of the pipe that is inserted inside of it. There is probably a little over an inch of pipe that is inside the actual fitting, and the connection seems strong- doesn't move or anything. will this become a problem? Should i cut the pipe out and refit?

Thanks,
S