Did someone slip me date rape or was i just really drunk.?

I know my limit, but there is variables that can change your limit from day to day. I can usually tell what my limit is as i drink. the night started at my friends house, we were all drinking before we went to a house party, i had four and i was drunk but not beyond drunk. i had eaten before i got there, maybe 3 hours before. thats all i remember about the night. I dont know how we got there, i dont remember who was there, i dont know how i left, i just woke up in my bed with an extreme hangover, i puked every half an hour until 8pm, then i trouble sleeping that night my nausea was gone but now i had a huge head ache and i was really tired but couldnt sleep. (very unlike me). I remember flashes of what happened, waiting for the street car, and one moment where i thought wow i need to get out of here. apparently i called my boyfriend 20 times asking the same questions he kept answering the same answers. i asked simple things like where are you, should i go home? i was at the party for maybe an hour and i dont even remember what the house looked like. I dont remember calling my boyfriend at all. i dont remember leaving i just remember thinking i need to get home, i remember feeling really exhausted. when i got home i passed out with all my clothes on and my jacket. i passed out around 11:40pm and i woke up at 11am the next day. im pretty sure i wasnt raped but i would like to know if i was drugged. i have been extremely wasted before where i drank way too much but that was a very long time ago, even then i remembered most things. i looked up things on the internet and i couldnt really tell because the same side effects are from being really drunk.Did someone slip me date rape or was i just really drunk.?i would go to the emergency room, the only way to know is a blood test