It sounds like an engine management issue, although usually you'd see an accompanying light on the instrument panel to warn you. However, if it's corrected itself after you switched it off and restarted it (which is often the way of clearing these electrical glitches) it may just be a one-off. If it's running fine then there should be no problems, although do mention it when you next take it for a service. If it does do it again before then, we'd suggest taking it for an inspection where they'll be able to hook it up to a diagnostics machine and tell you what may be wrong (if anything) and what the solution is.