A few months ago I started using 10s instead of 9s on my guitar which has a Floyd Rose. Anyway I had to put an extra (4th) spring in the back for the bridge to sit level. I didn't adjust the truss rod, should I have? and is there any way to know?

Look down the side of the neck and see if it is significantly bent. There might be a little bit of curvature, but that's normal.

Also, hold down a string at the first and last fret and observe the distance from the bottom of the string to the 12th fret.

If you can play it comfortably and the intonation is fine, then you shouldn't need to adjust it.
Thanks a bunch I was getting kinda worried about that. I couldn't see any curve and the intonation was fine.