How do you know if you've been drugged or just simply blacked out from drinks/ shots? What if you did not drink that much, is it still possible?

I can't remember how I ended up in someones bed or remember any details... I would not normally be close with this person or have any intentions with them. This happened twice with this person. Did I get drugged? Or just blacked out?

Updates
+1 y
What are the signs of being "drugged"? Did not get blood drawn to testing because did not think of it or know.
How do you know if you've been drugged or just simply blacked out from drinks/ shots? What if you did not drink that much, is it still possible?
Post Opinion