I don't think they class an 11 day LP as short. I think it's only if it's under 10 days.
11 days LP is an average. It's varied anywhere between 8 and 13 days in the last 9 months and I've never ovulated before day 19 (usually about day 21) with a cycle lasting anywhere between 28 and 38 days.

Normally they prescribe clomid if you aren't ovulating. Putting you on it when you do ovulate could result in multiples if you do fall pregnant.
Now I'm confused. I thought clomid was also to bring forward ovulation if you're ovulating too late and having a short LP? (did know about the multiples though)