No, don't do that.
Refrigerant, when mixed with A/C oil will bubble. That is normal. Spray some brake cleaner directly into the port for five seconds to clean out the oil and refrigerant, then blow the brake cleaner out with low pressure air (a straw and a mouth).
Then add three or four drops of houshold (sewing machine) oil to the port and watch for bubbles. If you see bubble, the port is leaking.
These ports do not commonly leak, the reason that you see bubbles when removing the cap is because the cap is a seal itself and traps refrigerant and oil in the port after any previous A/C servive.