Hi it does seem that you mat have had your Drink (Spiked) as you say that you was not yourself , you should be fine in 24 hours , if not by all means seek Doctors Advice ,
If your out again please don't leave you Drink untended there Terrible things can happen unfortunate , Please take care ,
The first thing I would question is how often do you drink, then what did you drink, how strong were they and finally how big was the drinks. If you are not use to drinking and the drinks were strong, you just might of been drunk.
The symptoms you described just sounds like a hangover to me.
But it can not be ruled out. If someone did slip you a "Roofie, Mikey" or what ever you want to call it, the only way to know is to have a blood test done. Even then there is no guarantee that anything will show up. The drugs do not stay in a persons blood system very long.
The 3 most common drugs that are used are: GHB (which is the one most people hear about), flunitrazepam and Ketamine.
The bad news is that some of the side effects of the drugs that are commonly use do have the same symptoms that you mentioned.
If you were drugged I am sorry, I know a little bit of how you are feeling. I learned just recently that a relative of mine was the victim of a date rape.
You have good reason to find out. If somebody did, they may do it to somebody else. Think about the next victim and get to the bottom of it quick.