Once you added your pair to a liquidity pool it will not be visible anymore. You will receive LP tokens in return, which are shown in the overview in the left down corner under the "your stake" title.
If you stake your LP tokens, you will receive rewards in return. Based on the amount of LP tokens you staked, weekly rewards will be calculated. When you staked all LP tokens 0.0 Liquidity pool tokens will be shown because your LP tokens are locked for the staking.
If you staked only a percentage of your LP tokens you will see amounts in both categories. as shown in the picture below. LP tokens staked are visible in the left bottom corner under "your stake" title and the LP tokens, that weren't staked are in the center next to "Stake" button.
You can also see the percentage of the share in the pool, once you are confirming your LP tokens.
(See the picture below)
After you claimed your rewards and withdraw your LP tokens, you can remove your liquidity from the pool and receive your pair back. The amounts will differ from the original investment depending on several market factors.