broken hydrometer/D rest timing

[MHBT]

Well my hydrometer broke and i am 7 days into a lager fermentation..I was about to check my gravity to see if its close to FG for a D rest..Question is should i leave the beer alone until i get a new hydrometer?..The activity has slowed down dramatically i dont want to miss the window for a d rest ..Should i start raising the temps? or wait for a new hydrometer? what would you do?..I pitched cold @ 45F and kept the temp steady at 50 the whole time..there is still a thin krausen.cheers