Is it possible to ingest cocaine without consent?

A couple days ago, i tested positive for meth and cocaine. i knew there would be pot in my system, but i never had anything to do with the others. i was at a party the night before the drug test, and sharing a shot gl. i also kissed a lot of people and touched a lot of surfaces. is it possible that i may have fotten it in my system through any of these things, or does it truely mean that i consinted to putting them in my body. it would bring me great relief to know that it was an accident. thanks.