Why does my washing comes out with stains on it.... they weren't there when it went into the wash...

Yes sometimes ink pens can be washed when we are not aware it was in someones pocket. I use straight ammonia and a cloth to clean my washing machine drum a couple times a year because these things have happened to me before. The ammonia will cut the grime and pen stains out of the drum. Then take a squirt bottle and fill it with white vinegar and squirt all around inside the drum of the machine. Run a wash without any clothes with the hottest water to clean the drum and clear out the stains. Do this to the dryer also and clean out the filters. Take the dispensers out from the washing machine and clean those too and your cleaning is done for a while. Apparently the ink has been in the drum of your washing machine and putting the color into your clothes. You can bleach out the white clothes that turned blue. Use the stain remover for colored clothes. Hope this will help you.