HI, I think you'll have lost them, but it's possible you could get them back from Time Machine.
What you do first is to enter Time Machine. You can do this if you have it in the taskbar at the top of your screen, otherwise you'll need to go in via Finder > Applications > Time Machine.app
Once in Time Machine, you'll see a series of folders that all look just like the Finder folder. Choose Pictures, and see if you can find your iPhoto Library.photolibrary
If you can't, then click on an "older" folder in the stack, and see if you can find it in one of your older TM backups. If you can, then right click (or ctrl click) and either Restore to... if that option exists, or Copy the iphotolibrary. Then exit Time Machine, go to Finder from your desk top, go to pictures, and paste the library back in.
It may be a long shot, and I'm not going to test it out to see if it works, but it might. Either way, you have nothing to lose, because you won't get it back from a secure trash empty.
Good luck, amnd let us know how you get on.