It's very unlikely that your oil pan gasket is the source of your oil leak as they almost never leak (even if the old one is re-used if the pan is removed).

It's more likely that you have another oil leak, such as a front or rear crank seal that's running along the oil pan making it appear as if the pan gasket is leaking.

Degrease the engine, run or drive the car and re-check it to see the exact area where the oil is coming from as you don't want to replace that pan gasket unless you must. It's not a fun job if done at home in your garage or driveway and you'll be very unhappy if the oil still leaks from another source afterwords.