No stain on bed sheet

Dear brother i have ocd which is an extreme level. This Ramadan i had dry urine on my trouser and i went to bed. I woke up i had a wet dream. I didnt check the the bed sheet properly. But i didnt see the stain i think it might have dried or becuase the bed sheet was dark i didnt see it. Even if the semen got on the bed sheet it would have been less than circle inside the palm. Now time is passing so should i wash that.