I have a piece of glass stuck in my heel, how do I get this little sucker out?

O.k., so I have a tiny piece of glass stuck on the heel of my foot. I tried to take it out with tweezers, but no go. Mu husbad tried too. I soaked it in warm water, but still no luck. This sounds so crazy, but some days it hurts..like now, and then others not at all. Can anyone help me at all?? Thanks for any advice possible!