Yes. You can show your house any time you want to. It's your house.
Legally your agent must bring to you all offers on your home, regardless if there is pending contract. (And that includes contracts that DON'T have contingencies to sell... But there is a possiblity of getting sued on those.) Most contingency contracts have a "48 hour First Right of Refusal" on it which states that if you do receive another offer, that the buyer on the pending offer will either take the sell contingency off and just go ahead and purchase, or bow out of the offer to let you negociate with the new buyer.