How do I know if I was drugged?

I went out with my best friend last Friday. We went to eat, and each had 3 rum & Cokes. I left my drink on the table for about 15 minutes when I went outside to have a smoke. I don't remember leaving that bar. The next thing I know, I woke up in a motel alone on the other side of town. The friend I went with said that we went to another bar, and then I disappeared. I didn't feel like I had had sex, but I did have bruises on the inside of my thigh. I am 30 years old and VERY happily married. My husband doesn't know what happened. I am TERRIFIED to tell him. How do I know if I was drugged? I'm also epileptic.