I don't have epilepsy but...

So I don't have epilepsy, but at the beginning of the month I had a seizure. I'd just retuened to my part-time job (at the local supermarket) that day after having a week off (I had the flu or something) and was feeling fine. Later in the afternoon though, when they put me on till, I would blank out for a few seconds while serving customers. I'd sort of jerk back like I'd just woken up or something. A supervisor noticed so took me off till and when I got to the door of the till room, I dropped it. I couldn't remember my code to get into the room so after calling my dad to come pick me up she put hers in for me. When I got in there I just collapsed onto the chair. She asked me some simple questions which I couldn't remember the answers to and when I could I had to think for a while before answering. All of this had gone on for about 10 minutes now. When Dad finally turned up I went out to the car (after dropping my bag repeatedly) and just collasped into the passenger seat. After we drove off I started having a seizure just as we left the carpark so Dad pulled over and tried to restrain me. After seizuring for a couple of minutes he turned around and went back into the carpark, calling out for someone to call an ambulance. I seizured for another minute or two then stopped. I came round to it around a couple of minutes later and couldn't recall anything that had happened within the last half hour. Apparently, before the seizure, my speech was slurred and I had poor co ordination. I haven't had one since and I'm pretty certain it's not epilepsy, though my sister has it. I was just wondering if anyone could offer some information about this? I've read that a lot of people experience at least one seizure in their life, so it's probably nothing, but any information would be great thanks!