It's not a silly question - you aren't the first to get bottom from top mixed up or not be able to tell, and you won't be the last!
You haven't said what type of bulbs - if its something like tulips, with taller flowers, they usually come up anyway - the growth starts at the bottom, does a U turn and comes up through the ground, heading for the light. They may flower later though, they've got further to travel... I'm guessing they weren't tulips though, cos they're easy to tell the bottom from the top... if they were smaller bulbs, so long as you didn't plant them too deep, they should be okay.

Geotropism - they know which was is up and the shoot will come out the base and then turn and grow upwards.

It is even possible that in about 18 months the bulbs will appear to have righted themselves.

If I'm unsure which way up to plant a bulb, I plant it on its side. The shoot always comes up and the roots always go down.

Thank you very much for your replies,much appreciated next time i will plant on the side if unsure.they were Alieums i dont think the spelling is correct part of the onion family have big globular heads when in bloom.