Lightning port malfunction?

For awhile now my iPhone 8 Plus is not charging consistently, even after being plugged in all night. It’s not the cable, because I’ve used several which all work fine to charge my iPad. So I think my lightning port is going bad. Is there a way to know for sure before I trek to the Apple store for an appointment? Or anything I can do to fix myself? I saw previous answers to use toothpick or cotton swab but I’m not sure I want to risk causing further damage. Any further suggestions? Thx.